The Dark Souls series, since its inception, has had a particular group who are DEFINED by their loyalty: the Warriors of Sunlight. The role of players belinging to this covenant revolves around jolly cooperation, helping any player who summons one of them with more energy and self-sacrifice than any other group. The NPC that represents them, Solaire of Astora, is also widely loved as the most loyal ally you can find in any of the games, being able to be summoned in many difficult battles (including the final battle) and always treating the NPC with friendliness and enthusiasm to help. The Sunlight Covenant is the only covenant that has been available for membership in every game in the series, and Sunbro players take their membership to the covenant seriously.
In the first Baldur's Gate game, the canonical party of Charname, Imoen, Jaheira, Khalid, Minsc, and Dynaheir were true companions. Charname and Imoen were foster and blood siblings raised together their entire lives, Jaheir and Khalid are Happily Married and were friends and comrades of Charname's foster father Gorion, and Minsc and Dynaheir also have a close though nonromantic relationship as per the customs of their people. This is what makes the first part of the sequel Shadows of Amnespeciallypainful. Irenicus kills Khalid and Dynaheir and ruins their bodies beyond any hope of resurrection and nearly drives Imoen insane by ripping out her soul.
The main characters of Bravely Default eventually feel this way toward each other even giving up opportunities to reunite with their actual families and live ideal lives. Their reasoning? The are already with the people they want to stand by.
In the Japanese version of Castlevania III: Dracula's Curse, Akumajou Densetsu, the uber-genki pirate/freedom fighter Grant Danesti immediately declares himself and Trevor Belmont to be true companions. The sequel game, Castlevania: Curse of Darkness, proves him right. As soon as Hector stats flailing about Trevor having beaten Dracula, Trevor immediately says he couldn't have done it without his friends. (Castlevania: Judgment's continuity twists this, for better or worse, by suggesting that Grant grew distant from Trevor due to a Love Triangle with Sypha and continued on his own path even after reconciliation. On the brighter side, Alucard remembers his teammates well even after centuries have passed.)
Castlevania: Aria of Sorrow has a scene. Soma, about to challenge Chaos, worries about that thing, only for everyone he's befriended throughout the game banding together to telepathically contact him and say, "Okay, you're Dracula... so what? You're our friend, and we think you can do this, and we're here for you." Once he wins, they all congratulate him, and they all return in Dawn of Sorrow to cheer him on and help him out again.
Cave Story shows this forming, but it only comes to fruition if you get 100% Completion. Quote and Curly Brace go from fighting each other, to fighting side-by-side, and they even convince Recurring Boss Balrog to help them at one point. In the Standard Ending, this is as far as it goes. But if Quote saves Curly after the Core battle, and then restores her memories, she gives him the Iron Bond: "Your tie to Curly Brace, the only warrior you would trust your back to." The endgame then involves them fighting the True Final Boss together as Back-to-Back Badasses, with Balrog swooping in to rescue them at the end. And then the three of them decide to move someplace with a nice view and live together.
Chrono Trigger: All the playable characters except Magus are this, and don't really fit any of the subtropes either. The only ones that knew each other before the events of the game are Chrono and Lucca, yet all of them hit it off and get along perfectly from the moment they meet each other.
Dissidia Final Fantasy, the ten main heroes in this crossover are true companions and several smaller, fluctuating groups are as well. The concept serves as a major overarching theme across their stories.
Hawke's group in Dragon Age II fit this trope well, with their conversations showing that each are willing to support each other. Varric looks out for Merrill, protecting her at night when she walks alone, drinks often with Carver, even as they rail on each other. Aveline and Isabela become Vitriolic Best Buds by Act III, and many of the characters display an uncommon tenderness towards Bethany. Like the first game however, several of the team simply do not get along, especially in the case of Anders. Fenris and Sebastian will even discuss turning him or Merrill over to the Templars, with Fenris pointing out they can't do it without Hawke's approval.
The biggest one, arguably in the whole series, would be have to be the relationship between Hawke and Varric. Varric never leaves Hawke's side throughout the entire game, and even in the Framing Device, makes clear how much he values Hawke's friendship. In Inquisition, it's revealed that he was the only one who Hawke stayed in constant contact with in the four years that they dropped off the map. Even under a long interrogation, he lied about this, and about knowing their real location, in order to protect his best friend. If Hawke is killed, Varric is utterly devastated.
The chosen ones of the Red Night in 11eyes refer to themselves as true companions several times, though sometimes it feels like it's being used to hold team spirit together as the challenges get tougher. Their group even has a motto. "For our friends and tomorrow!"
One character gives a passionate speech about what it means to be true companions to another character in Ever17.
Exit Fate: To varying degrees, the Elysium Army — particularily Daniel, Ljusalf and Ayara, who join together early on. At one point, when you've amassed many followers and generals, Ayara runs off, believing that you don't need her anymore, and you have to track her down and convince her that she's important too. And then there are Daniel's friends since childhood, Angel and Jovian - much of Daniel's grief stems from his fear that Jovian betrayed him due to their conflicting ideals. He didn't. Jovian would never betray him. Ever.
Final Fantasy IX has a similarly strong message about the importance of true companions and how what you do and who you love is more important than where you come from. This is most strongly illustrated during the You Are NotAlone sequence, when Zidane's tendency to help people for no real reason other than it's the right thing to do pays off in spades. Broken in mind and spirit, he's in the middle of a Heroic BSoD when his friends risk life and limb to save him, because he'd have done it for them. It's absolutely beautiful.
Final Fantasy V. The four Light Warriors hold together through failure, poisonings, and the death of one of their own without fail. Galuf even calls a retreat when he's attacking Castle Exdeath to go and rescue the other three, alone. And in the ending, a lonely Krile is told by the other three that there's no way she's going to be alone when they're around.
It is revealed in Crisis Core that even Sephiroth had True Companions through Angeal and Genesis. Though that was not enough to stop Genesis and Angeal from leaving Sephiroth behind when they discovered their true origins and went rogue.
Final Fantasy X. Although Tidus functions as the narrator, the story as a whole is centered around the exploits of Yuna's guardians, as mismatched and misfit as they were, in their efforts to protect her and defeat Sin. It's carried on to a lesser extent in FFX-2, with Yuna as the main protagonist, though much of the original cast has disbanded and moved on. Tidus' sword is even named "Brotherhood," and powers up as he grows closer to the party.
Somewhat played with in that most of the party were already True Companions to Yuna before her pilgrimage: Rikku is her cousin, Kimahri and Auron knew her father, and Wakka and Lulu grew up with her on Besaid.
The six main characters of Final Fantasy XIII form a powerful bond thanks to the fact that the entire world wants to kill them. Especially poignant with Fang and Vanille, who come from an egalitarian culture where everybody shared everything and took the same last name. At one point when Vanille's hit rock bottom, Fang encourages her by reminding her that they have a new family now.
The cast of Final Fantasy XV are pretty buddy buddy. The game's even been compared to taking a road trip with a bunch of friends from college.
Cid Sophiar: Those ain't your bodyguards...they're your brothers.
Class Zero, the heroes of Final Fantasy Type-0 are a class of fourteen teenagers who have been raised by their government as living weapons of war. Due to their life of constant military training they aren't able to make friends with other kids their age, so they form a surrogate family among each other. They're so close that in the end they die together, and when the two surviving members find the others' bodies, they are all holding hands.
Guy from Final Fight has this relationship with Cody Travers, Mike Haggar (and arguably his daughter Jessica too), and likely with his sister-in-law Maki.
"In times like these, it matters not what our blood ties are. We are family."
Right before the final chapter, Ike states in a Rousing Speech that he finally understands what it means.
Golden Sun games have a very strong focus on family and on friends that are like family. It gets lampshaded in Dark Dawn when an NPC comments on the wide variety of friends you have with you from so many different backgrounds, and how close-knit you've become anyway, and draws a comparison to family.
In Granblue Fantasy, this is Played for Laughs, of all things. As it turns out, Lowain and his pals Elsam and Tomoi could easily score with girls if they tried, but they're way more interested in hanging out and doing stupid things together than actually settling down with a girlfriend. The narration itself ends up calling it "the greatest bromance".
Knights of the Old Republic is all about this. In the original game and the sequel you have a team of misfits (some of whom have very good reason to resent each other), and yet the team sticks together by the player character's leadership. Then the sequel turns right around and Deconstructs it by giving a slightly discomforting reason as to whyyour party forms around you.
The Survivors in Left 4 Dead (even though certain characters won't admit it). It can be summed up in Bill's final message to the group "Take care of each other, you guys are the only family I've got left!"
The level of friendship you form with your team in Persona 4 is truly heartwarming; not surprising in a game where building social links increases your potential and efficiency in battle. Most of the storyline, apart from being a supernatural/murder mystery, is about the bonds you share with others. In the final battle of the game, your teammates sacrifice themselves one by one to protect you; don't worry, they all live.
That goes for its predecessor Persona 3 as well, which was the game that first introduced the social link aspect. In regards to the actual storyline, the bond between the members of your team — SEES — grows stronger and stronger as you progress through the game. By the end, all the members of SEES have become True Companions. It's played with a bit compared to 4 and 5, as they become True Companions on more of a professional level than as best friends. Most of the time, the Juniors and Seniors tend to keep to themselves in their social lives; by the end only Yukari and Mitsuru have truly become best friends. That said, as mentioned, professionally they trust each other with their lives.
The party in Persona 2: Innocent Sin become incredibly close by the end of their adventures, partly because they already knew each other when they were children. Sadly, the game ends with them having to completely erase their memories of each other in order to save the world. Even then, Tatsuya's refusal to forget about his friends is what jump-starts the plot of Eternal Punishment.
The main team in Persona 2: Eternal Punishment are troubled adults who initially have trouble getting along with each other, but their shared tribulations eventually forge strong bonds of friendship/respect between all of them.
Like its predecessors, the bond the Phantom Thieves share in Persona 5 is incredibly tight-knit, in large part because all of them are victims of abusive authority figures, hence why their modus operandi is to reform said authority figures by 'stealing their hearts'.
The main plot of Little Busters! revolves around a group of five childhood friends who are all extremely close. Naturally, since this is an utsuge, the 'true' route involves them fighting and their entire relationship breaking beyond repair. Naturally, since this is a Key/Visual Arts utsuge, they figure out a way to repair it anyway.
Every party in the Mother series consists of four friends. There are three total, and all are fine examples of this trope.
The whole premise of Mass Effect 2 is to not only gather a team of soldiers, assassins, and scientists, but also develop strong friendships with them. To do that, Shepard has to help each of their teammates resolve their respective pasts, not only to earn their loyalty and friendship, but also to show that they are a True Companion to them. Otherwise, Shepard's teammates would only think of their as their boss, rather than as a friend, and they wouldn't be as motivated to follow their lead, thus costing them their lives in the suicide mission.
Shepard views turian squadmate Garrus Vakarian and quarian squadmate Tali'Zorah as such in terms of them watching their back when walking through hell. Shepard also assures asari squadmate Liara that s/he considers her one when she goes through a little angst about not joining him/her in 2, especially since it was because of her that s/he was brought Back from the Dead in the first place. Dr. Chakwas, the Normandy's medical officer, considers Shepard, "the center of her galaxy," a true companion. Chakwas also considers Joker a true companion, in terms of helping Joker with his brittle bone disease when he needs her. Joker views Shepard as his true companion in terms of being on Shepard's side 100% despite the occasional sass-laden conversations. Joker is in fact the only character in the trilogy who is completely guaranteed to be by Shepard's side for the whole thing. In-universe example: Krogan use the term "Krantt" for true companions that serve as battle-brothers.
Mass Effect 3 takes it further, especially considering that of your possible 7 squadmates, 4 of them are your original crew, plus Joker, Chakwas and EDI. The final conversations you have with them before the final assault on Earth:
Shepard: Shepard and Vakarian, storming Heaven. I can think of worse things. Garrus: Heh, I'll meet you at the bar.
The trope is most prominent in the DLC quest, Citadel. In the first half, Urdnot Wrex temporarily rejoins Shepard's squad, and as Shepard and their squad hunt down and defeat the Shepard clone, they do so together, as a single unit and family designed to protect each other at any cost. Then, by the second half, Shepard invites all of their squadmates, former and current alike, to Admiral Anderson's apartment for a party, to celebrate their friendship and teamwork throughout the entire Mass Effect trilogy, before their inevitable final push against the Reapers. The party then ends with a group photo of Shepard and all of their squadmates, which truly cemented their friendship.
Metal Gear series: Solid Snake has one of these with Otacon, primarily, and later Sunny. Even more so, his father Big Boss in Metal Gear Solid 3 and especially the PSP spin-offs. It's the fracturing of this crew that has retroactively become the basis for the conflict of Solid Snake's story.
Even more so prominent in Metal Gear Rising: Revengeance, with virtually everyone in Maverick going back at some point or another: Boris was vital in helping Raiden rescue Sunny from the Patriots, Kevin and Boris both worked together in the past at an NGO for the UN, and Kevin and Courtney were college buddies. Eventually, all of them ended up working at Maverick Security Consulting. The only real odd duck is Doktor, who primarily joined For Science!, but he too ended up becoming a part of their weird family.
NieR: Nier forms one with the maladjusted but sympathetic freaks he meets along his journey, extending his Papa Wolf nature onto them. Even the arrogant Grimoire Weiss sees the group as friends.
One Piece Unlimited World Red: Unsurprising, given the series it's spun from, but the concept of True Companions is a heavy theme in this game's story, not just on the hero's side, but the villain as well.
Planescape: Torment, if one plays it with a team, that team appear to be true companions, often jumping to the enthusiastic defense of teammates over insults and slights by others. However, this is actually a subversion because: it's the Nameless One's Mark of Torment that's magically compelling the team to stay together.
The Eight Companions of the Avatar, who accompanied him on the quest to Avatarhood, are this throughout the Ultima series, especially games four through seven.
In the Pokémongames, much emphasis is placed on the bond between Pokémon and their Trainers. Everyone feels this way for at least one specific Pokémon.
The Nuzlocke Challenge puts severe limitations on what Pokémon you can catch, and forces you to release or permanently box any Pokémon that gets KO'd for real. Several players, including the creator who initially challenged himself for the lulz, have admitted that the challenge actually makes them feel much more passionately about the few, fragile Pokémon they have, especially species that they would normally pass over without a second thought.
Professor Layton: The Professor's true-companion group consists of a pair of children — his apprentice, Luke, and his ward, Flora.
Resident Evil series: Despite the Ship Tease found in some of the games, Jill Valentine and Chris Redfield are like this. Jill is willing to sacrifice herself to save Chris from Wesker. While Chris is on his next mission, the moment he gets wind she might still be alive he drops everything else to find her.
Sakura Wars takes camaraderie very, very seriously, with the main force, the Teikokukagekidan, having reinforced it to its most extreme in multiple games, blurring the line between friendship and family.
You become true companions with (most of) your fellow newly recruited Samurai in Shin Megami Tensei IV. That is until events cause the fellowship to break. By the end of the game, at least 2 of the 4 Samurai will be dead at the hands of each other.
The Double Subversion comes in Shin Megami Tensei IV: Apocalypse. If you go with the Bonds route, when Walter and Jonathan are temporarily resurrected by Satan, they hold no ill will against Flynn, Isabaeu, or each other, and team up with them against the Final Boss without a second thought. Even Navarre, the "most of" in the above point, is included in the end by Walter. In addition, the new Player Character and his party count as this.
The main trio - Sonic, Tails, and Knuckles - exhibit this, especially with the former two. Sonic and Tails' team in Sonic Advance 3 is even called "Unbreakable Bond".
Team Dark consisting of Shadow, Rouge, and E-123 Omega have surprisingly become this throughout the course of the series as they often show combat and moral support. This is particularly well-demonstrated with Shadow and Rouge, as in Sonic the Hedgehog (2006), when Shadow learned that humanity will use Omega to seal him in the future, Rouge tells Shadow that, despite this revelation, she'll remain by his side.
Star Fox has this for both teams: the main team Star Fox are like family to each other, but on recent plot themes, they have then become disbanded or at least one of them would leave to fly solo. Ironically, Star Wolf experiences this in reverse - Star Wolf originally has Wolf, Leon, Pigma, and Andrew. The last two were kicked out because of the lack of loyalty and code of honor, and were replaced by Panther. Panther is then a permanent member, and the trio have become so closer than ever.
While Suikoden often consists of many combinations of the Five-Man Band, each army of 108 stars ends up being a macro version of this trope. They fight, go on adventures, drink, party, and judge cooking contests together as a sprawling enclave.
The crew of the Sunrider grow into this dynamic over the course of their war with PACT. Asaga and Chigara were already best friends before joining the crew, Kayto and Ava were childhood friends who now work together as the ships captain and executive officer, Sola finds common ground with Asaga as a fellow Ryuvian princess, and Icari and Kryska end up forming a powerful friendship despite their different backgrounds and personalities. Kayto even comes to regard them all as his family.
The groups close-knit unity starts fraying in Sunrider Liberation Day, with Ava and Asaga beginning to suspect that Chigara is a Prototypespy and Asaga growing resentful of her best friend for overshadowing her in terms of heroics and closeness to Kayto. This culminates in Asaga attempting to murder Chigara in a jealous rage only for Claude, the ships quirky goofball doctor, to give an impassioned speech that snaps her out of it.
Icari and Kryskas status as true companions is cemented during the Liberation Day massacre. As everything goes to hell all around them, Kryska reveals that her Alliance superiors have given her orders to shoot Kayto and pulls a gun on him, only for Icari to intervene. The two women hold each other at gunpoint, only to break down crying as they realize that they cant bear to kill each other. Kryska then rips off her Alliance insignia and rejoins the Sunrider, helping them to escape from the carnage and even fighting against her own countrymen.
Kryska: I may have been a loyal officer of the Solar Alliance but not even that means anything next to my comrades in arms! Ill kill all of you to protect them!
In Tales of Symphonia, towards the end of the game, the main party is split into multiple groups as a result of a trap. Lloyd and his Soul Mate go and rescue their friends, and Lloyd goes to each event, where the characters are being tormented by their own fears and demons. He accepts them for who they are and they manage to break the trap. This is most prevelant in Genis & Raine's torture, where they are singled out for being half elves. Lloyd disperses their fears and returns them to the group.
Also subverted by Zelos, if you choose Kratos' path: Lloyd never fully grows to trust him as a member of the team, and as a result, when he reveals his status as a Double Reverse Quadruple Agent, rather than faking a FaceHeel Turn and going off to act as The Mole so he can enable a later Big Damn Heroes, he decides to commit Suicide by Cop and fights the party, forcing them to kill him and delegating the remainder of his story role to Kratos. At the end, he laments that he was never completely able to gain Lloyd's trust.
In The Reconstruction, though your guild doesn't start off like this, it eventually ends up this way by the end.
Numerous Touhou characters have formed what are probably the most bizarre crews of true companions in existence, a combination of a regular dysfunctional family, disgruntled employees, and a Badass Crew that will brutalise anyone that dares harm any of their fellows. Let's analyze them one by one.
The household of the Scarlet Devil Mansion are united against all threats, especially because they are the obviously-Western supernaturals in a Japanese setting.
The Yakumo household blur the line between true companions and actual family. Chen is often depicted as having two mommies, Ran and Yukari, in fan works. Official source states that Chen is not just Ran's student, she's like a daughter to her.
The Eientei household will defend their members viciously from any external threats, especially due to their circumstance: they house at least three wanted Lunarian fugitives, two of which are eternal enemies of the state.
Say what you want about the atrocious beginning of Kanako and Suwako's relationship, but in this modern time, they are Sanae's two mommies.
Subterranean Animism plays with this. The Komeiji household is an example of true companions, but the justification for this is because the Komeiji sisters can read into any sentient beings' mind, which is how they won the loyalty of their pets: they are the only ones who can understand their pets' feelings.
in Undefined Fantastic Object, this is one half of the Player Punch of fighting Byakuren's followers, the other half being Fantastic Racism. They aren't some kind of crazy cultists seeking to release a nasty sorceress sealed in the demon realm, they are Fire-Forged Friends who aim to liberate their saintly leader.
Chapter 8 of Valkyria Chronicles has Welkin refer to the main players in Squad 7 as a family, with himself and Alicia as the father and mother, Rosie and his sister Isara as the daughters, and Largo as the grandfather. This scene is referenced again, as well as the reactions they all have to certain events in the game.
Leonhardt and his true companions (Borgnine, Ellis, Vira-Lorr, Zerva, and Winfield) in Agarest Senki have a bond that is so strong, that they actually stick together with the descendants of Leo for four more generations. And this group is one of the few Combination Attacks that are EX Combos.
World of Warcraft's two big factions the Horde and the Alliance both exemplify this trope, though it's arguably much more prominent in the Horde's storyline. Always a theme between the Orcs, Trolls, and Tauren of Kalimdor, it became a universal Horde theme after the Siege of Orgrimmar event (although not all of the Horde's members were totally on board with this idea).
Vol'jin: This world don't give us nothing, <player>. It be our lot to suffer... And our duty to fight back. This Horde be our family! We may not always see eye-to-eye. We come to blows before. But when we work together - ah - there's nothing this Horde can't do.
King Varian Wrynn and his companions Valeera Sanguinaar and Broll Bearmantle. Unfortunately, their interactions are mostly restricted to comics and novels, with barely anything referencing it in game. At least Valeera and Varian can team up in Heroes of the Storm. Also, Valeera shows up in several questlines and in some cutscenes with the King of Stormwind. She has also continued to support Varian's son Anduin.
There are plenty of other examples, one of the most prominent being the Sons of Lothar. This was a group created to carry on the legacy of Anduin Lothar, and stop the Legion. While they became separated across galaxies and indeed timelines, they never lost faith in each other and turned to each other in times of need. This became a plot point when in the Legion expansion, Turalyon manages to contact Khadgar: launching the second half of the expansion's plot. Khadgar instantly trusts Turalyon's message, and mobilizes all the forces of Azeroth to respond.
another notable example, on the level of whole cultures is the Blood Elves and the Nightbourne: or as they call themselves, Sin'dorei and Shal'dorei respectively. Both share the experience of magical addiction and of rebelling against leaders who worked with the Legion. Both were also rejected by the Kaldorei or Night Elves, because of their mistakes.
The title organization of Overwatch is indicated to have operated like this. The Archives events show both the Strike Team and Blackwatch (as well as the command team of Morrison and Ana) to be incredibly close, cracking jokes and offering support when needed, and the comics show this as well. In the "Are You With Us?" teaser, Winston says that "they tore our family apart" in reference to Overwatch's disbandment. And when he activates the Recall, many former agents, including McCree, Genji, Reinhardt (and his squire Brigitte), Mei, and Tracer, accept the call back to the organization, with Tracer going as far to respond within seconds.
Shantae and her three best friends, Bolo, Sky, and Rottytops are close as can be. Whenever Shantae starts getting down herself, the other three will be there to get her spirits back up. For her part, Shantae will do anything to help the others. Best shown in the Friends to the End DLC, in which Bolo, Sky and Rottytops go through a lot to bring Shantae back after she is corrupted by dark magic.