The game is set in the fantasy world of Heryon, which has been invaded by the mysterious and technologically advanced Archelites. For the past 30 years, the people of Heryon have managed to hold the line against the Archelite invaders, fighting back with the aid of magical crystals. In response, the Archelites released a deadly disease known as the Corrosion, which warps people into horrible, misshapen monsters known as the Corroded. In the midst of this war, a disillusioned young soldier known as Daryon receives a letter from his sister, the Sanctorium priestess Selene. She informs him that their mother has contracted the Corrosion and that she needs his aid to find a cure. Upon receiving the letter, Daryon plants his dog tags on a corpse and deserts the military to join his sister. The game follows the siblings as they travel across Heryon, searching for any clues that might lead them to a cure for the Corrosion and recruiting allies both new and old to join them on their quest.
No relation to End of Eternity, the Japanese title for Resonance of Fate.
Edge of Eternity contains examples of:
- After-Combat Recovery: HP and MP are fully recovered after battle, at the cost of some Team Energy.
- Artificial Limbs: Ysoris's legs and right arm are cybernetic.
- Back Stab: Attack an enemy from the back deals more damage. Daryon in particular can equip a skill that causes his attack to be an automatic backstab and even (attempts to) reposition him behind the enemy for more backstabs.
- Bittersweet Ending: Daryon sacrifices the Archelite fleet and his voice to save the world, which means all the civilians aboard the ships are either stranded on a world that hates them or dead, and the non-essential tower prisoners, including Sil and the siblings' mother, were tortured to death by the Final Boss. Meanwhile, Selene still hasn't found a cure for the Corrosion, so she still potentially faces the death penalty due to Ilvana's Decree, but she's still determined to find one, with Oboros giving a lead that the disease is caused by the gods being weakened by crystal mining.
- BFS: Daryon's weapon of choice is one of these.
- Body Horror: The Corroded form of Sil is not pleasant to look at. She's misshapen, twice as tall as she was before the corruption, and red, fleshy tendrils falling from her head and neck make a mockery of her red hair. Her face is still recognizable but is marred by a massive Glasgow Grin.
- Body of Bodies: Corroded can merge their bodies, creating giant monsters called Conclaves. They can do this even if they've been killed, which historically caused huge trouble due to corpses of Corrosion victims being thrown into mass graves.
- Bothering by the Book: Selene reveals to Daryon that she got herself released from her job with the Sanctorium due to a combination of this and Reverse Psychology. She did her job as an archivist so well that she became "a pain in the butt." Whenever they would try to establish new edicts, she would burst in with tablets of older laws and forgotten Epigrams, Sacred Texts that contradicted whatever edicts they were writing. She drove them so up the wall that they decided to "promote" her from archivist to midwife. She, however, had already become so popular with the midwives that they immediately elected her as their representative on the Council Ring, which meant that she was right back with the elders to drive the demands of the midwife corpus. They freaked out - they had thrown her out by the door only to see her climb back in through the window. They then decided that the only way that they could be sure to be rid of her was to task her with the honor of finding a cure for the Corrosion, there being rumors running around that it was the worst mission they could possibly give her and that she would be mortified to accept such a perilous mission, rumors which she had started.
- Broken Bridge: A literal one outside of Herelsor. It only gets fixed after you reach the next chapter.
- Bumbling Henchmen Duo: Derek is an Insufferable Genius mage with an inferiority complex, while Gavin is Dumb Muscle and a former monk. They spend more time arguing than fighting.
- Changed My Mind, Kid: Ysoris is initially willing to send Daryon and Selene into a hopeless fight, but after Taranis confronts him he has a crisis of conscience and follows after them to offer his aid in the battle.
- Critical Existence Failure: In the absence of status effects, party members and enemies will both be fully effective as long as their HP are above zero.
- Cuteness Proximity: Selene breaks character and screams like a fangirl when she gets to buy a Nekaroo Farm.
- Deuteragonist: Selene.
- Doppelgänger: Oboros, the Final Boss, is some kind of crystal-powered lifeform who can copy the body and mind of anyone he sees. The only indicator that they're different is their glowing yellow eyes.
- Down in the Dumps: The dungeon of chapter IV is a dump full of ancient discarded machinery.
- Dual Wielding: Myrna dual-wields her knives.
- Fallon can dual wield in her limit break.
- Dying as Yourself: Sil's mind comes back from the Corrosion in her last moments.
- Elemental Powers: In Heryon, crystals contain magic and can be equipped to weapons so that the wielder can cast elemental spells. Some monsters also possess elemental magic.
- Emotion Eater: Pilitches, the setting's equivalent of chickens, feed on sorrow. An optional encounter late in the game implies that this is because nature itself has come to hate humanity.
- Energy Absorption: Theia's combat style revolves around absorbing enough energy from her enemies with drain attacks to power her superweapons.
- Exposed to the Elements: Myrna wears her skimpy outfit through the icy Pass of Olphara, without any complaints.
- Foreshadowing: If you gather enough Crystal Fruits for the related side-quest, Grant will tell you that the first one he ever found is somehow getting bigger, and Selene wonders if it has anything to do with an ancient civilization's (called the Venati) fabled ability to grow crystals. On your way to the Cathedral of Ulakaris (itself a remnant of the Venati) late in the game, you can see many Crystal Fruits that are a lot bigger than the ones you've been collecting for Grant.
- Gameplay and Story Segregation: During your trip to the Tyr-Caelum clockwork field, you discover that the corrosion isn't airborne, waterborne, or whatever-borne. This allows you to summon a nekaroo in the corrosion-infested field, where previously you'd get a giant red X on her mugshot. Unfortunately, you still can't summon her in any other corrosion-infested field.
- Game-Breaking Bug: There is a Hold the Line mission at Tyr Caelum late in the game. On PS4, this is very prone to freezing and unresponsive controls. If you finish the battle, you get a blank screen with music playing. The only thing you can do at this point is force quit, retry from your last save, and see if you get lucky before your patience runs out.
- Geo Effects: Props lying around in the world aren't just decorations; they either cast buffs on combatants who move onto them, deal damage, or can be used to attack.
- Gods Need Prayer Badly: Events in chapter 3 imply that this is the case for Heryon's gods.
- One goddess in particular has an interestingly unstable dynamic; since she's the goddess of forgotten things; barely anyone remembers her own followers, let alone her. In the sidequest, you have to help her last initiate become her new priestess. Everyone forgets she exists, and her crush is left holding an artifact that tortures him with the forgotten memory.
- Godzilla Threshold: The Archelites believe the Consort has successfully created an Ascendance ritual large enough to destroy their entire spaceward fleet, so they approve of nuking the continent. Myrna is disgusted enough to prefer dying than living with the shame.
- The Final Boss considers the Corrosion and humanity's Corrupt Church as justification to hit the reset button on the planet.
- Golem: Venati golems are floating brick walls with a purple glow. Then Fallon sticks an AI core into one to turn her into a party member.
- Gosh Dang It to Heck!:
- Characters say "ash" where one might expect "ass," e.g. "ashbag" instead of "asshole."
- When you meet the mercenaries Gavin and Derek in the Elysian Fields, Gavin says "Son of a biscuit!"
- Greater-Scope Villain: Whatever the Noah are, they pushed the Archelites to the brink, driving them to desperately declare war on a primitive civilization just to get the resources they need to fight back.
- Hack Your Enemy: Ysoris can hack machines and robotic enemies with his Jamming spell.
- Handicapped Badass: Ysoris's body has been ravaged by the Corrosion, both his legs and his right arm have been replaced with cybernetics, and he openly admits to being in constant pain. He also swings a mean scythe.
- Horse of a Different Color: Nekaroos are giant cats with two blue-tipped tails. They're fast, can track down and dig up buried treasure, and hate Corrosion.
- Human Aliens: The Archelites are identical to humans. From the player's perspective, it's implied that the people of Heryon are the actual examples of this trope, while the Archelites are actually humans from Earth.
- Jeanne d'Archétype: Selene. The Gods started talking to her when she was twelve years old and even taught her magic. According to them, they needed her help with something really important but she stopped hearing the "voices" soon after joining the Sanctorium.
- Jiggle Physics: It isn't very obvious because of the default camera angles, but Selene's breasts bounce every time she moves.
- Kryptonite Factor: Downplayed but Oboros is singularly vulnerable to catching the Corrosion through physical contact, notably fleeing a fight that he was certain to win when Ysoris used an ability fueled by his Corroded heart. It's probably no wonder that he ended up corrupted when Herrana stabbed him with her Corroded arm.
- Leaked Experience: If at least one party member is conscious at the end of a battle, then KO'ed members will also get full experience.
- Light Is Not Good: The final dungeon is themed around the Light element, and all enemies there are weak against Darkness. Oboros, the Big Bad, is an envoy of the gods.
- Limit Break: Unlocked after Chapter 3.
- Daryon throws his sword at the target, then leaps up and slams onto the target, beats them up with his fists, and uses a sword combo for the finisher.
- Selene unleashes a gigantic summoning circle to pelt the target with three crystal meteors.
- Ysoris unlocks a violin case containing his corroded heart and uses it to summon tentacles that pummel the opponent into the ground.
- Fallon dual-wields pistols, throws an armful of grenades, fires an orbital laser, and then turns away and triggers a detonator.
- Theia heals everyone. (This is mostly because one of her spells is a pseudo limit break)
- Magic Staff: Selene uses a staff both for melee combat and to cast spells.
- Magitek: Some Heryons have salvaged the technology from downed Archelite ships and seek to create a fusion between magic and science. So far, they've made a mint building a Company Town in the ruins of an Ark-class Archelite cruiser.
- Mechanically Unusual Fighter: Only Daryon, Selene, and Myrna use regular MP. Each other character has a gimmick replacing it:
- Ysoris has Energy Points (EP), which are gained by absorbing attacks with his Defend Command, making him the party's tank.
- Fallon has 5 Ammo Points (AP) that she can restore by reloading, with each ability costing between 1 and 3 AP. On top of that, some of her abilities are enhanced if used on either the first or last bullet.
- Theia also has EP, but gains it by hitting enemies with her normal attack or through the Syphon Orb and Trap Orb abilities. She starts each fight with 0 EP and gains it very slowly, but her spells are strong and get even better if she has more EP than they cost.
- Mercy Kill: Daryon performs one for a soldier who is suffering the later stages of the Corrosion.
- Mighty Glacier: Ysoris is painfully slow, but has extremely high defense and HP, and can attack multiple enemies at once.
- Motivational Lie: Myrna admits to Daryon that she gives bogus fortune readings to soldiers in order to inspire them to fight for a better future.
- Naked First Impression: Daryon and Selene first encounter Ysoris while the latter is at his home in the junkyard, charging his prosthetics in the buff.Daryon: That just redefined awkward for me.Ysoris: The Corrosion didn't affect my sense of hearing, you know.
- No One Gets Left Behind: Selene refuses to leave Daryon behind on Olphara Pass, despite Myrna's protests.
- Not in This for Your Revolution: Daryon has generally grown disgusted with "dying for a greater cause", and repeatedly lashes out when he's told that he has a great responsibility to save the world. The only reason he's fighting is because his family will die if he doesn't.
- Plot Tunnel: When you set off to find Alpharius on the Kaladaan Coast, a message box pops up, sayingA sense of foreboding fills our heroes. If you step further, you will not be able to go back for a good while. Do you wish to proceed?
Yes/No - Our Gods Are Different: The crystals littering Heryon are capable of sapience, and the largest among them are worshiped as Gods.
- Plot Detour: The party didn't know about Oboros and only went after him under duress. It's only after they realize his strength and the nature of his goals that they decide to focus on taking him down.
- Powers as Programs: Crystals can be freely added and removed from weapons, and give stat bonuses and spells.
- Precursors: The Venati were an advanced civilization whose tech tree revolved around growing crystals with magic. They were wiped out when a giant meteor forced the gods to overexert themselves catching the meteor and fell into comas, which de-powered magic for a few centuries.
- Refusal of the Call: A Venati prophecy found in their cathedral implies that Oboros decided on his genocidal plan when the human he was supposed to help rejected him. Kora admits to the encounter but claims that Oboros asked him to do the same thing that the doppelgänger ended up doing on his own. Daryon doesn't buy it.
- Sequel Hook: Because Kora and Oboros derailed the party's plans, the Corrosion is still out there : we never got to see the place where Ysoris was healed and we don't know the purpose of the gem Ysoris took from the Corroded's "godess" in the first Clockwork Field.
- Shout-Out: The crashed Vanguard spaceship houses a very snarky AI with a susiciously familar voice filter.
- Sky Pirates: Fallon declares herself to be one but since she's apparently the only (first ?) one around, the title confuses everyone around her. The party wants to travel in her airship.
- Sinister Scythe: Ysoris wields one.
- So Long, and Thanks for All the Gear: Myrna ends up betraying the party and leaving. Thankfully, they have no gear tree so their gear is low-level at best, and you unlock the next tier of crystals after their fight.
- Stop, or I Shoot Myself!: Heranna threatens to commit suicide at the start of the game to stop her adopted children from seeking a cure for her disease, since doing so would put their careers at risk, and, in Daryon's case, his life, since the army considers desertion a capital offense.
- Taking You with Me: Daryon and Selene's mother sacrifices herself to stab Oboros in the back.note .
- "The Reason You Suck" Speech: The Final Boss literally screams at the party that everything bad happening to Heryon is all humanity's fault, since the Consortium declared a war they couldn't win twice, and then cannibalized their own gods for weapons, which weakened the gods and allowed the previously-contained corrosion to spread, and that his purge is the only way that humanity can redeem itself. Selene counters by revealing Oboros failed his trial as well (he can't hear the gods either), which means his apocalypse is not endorsed by the gods, and nobody asked him to 'save' them by burning 99% of humanity to death and enslaving the remaining 1%.
- Treants: A treant is the focus of one side quest. It looks like a normal tree, apart from several growths shaped like human faces. It also is almost exactly a normal tree, apart from its ability to speak, so it can't move or hit people. Unfortunately, treants are very good at speaking. Their favorite trick is manipulating people into murdering each other so it can feed on their corpses. In a pinch, it can also summon monsters by imitating their mating calls.
- Unexpected Gameplay Change: Some quests repurpose the combat mechanics into a puzzle game or tower defense.
- Weather of War: Weather conditions such as rain or snowfall influence the power of certain elements, indicated by their icons being colored in or crossed out on the HUD.
- Wham Episode: Ysoris destroys the anti-corrosion field generator then runs from the party and goads them to follow him deeper into a Clockwork Field, where they eventually find him seated in front of a house lost in the middle of the corrupted land. And then the house's owner, who bears no sign of the Corrosion, comes out and greets them. This allows Ysoris to demonstrate his point about the disease : Corrosion doesn't spread biologically, it simply appears in victims.
- Villainous Breakdown: By the time the party reaches the Final Boss, what is left of his temper is gone and he gives off a Motive Rant constantly shouting.
- You Shall Not Pass!: Daryon pulls one of these on the corroded humanoids at Olphara Pass to give Selene and Myrna a chance to escape. Luckily for him, he triggers his Limit Break.
