Tsuyokute New Saga, roughly translated to, A New, Stronger Saga is the story of the hero Kail, the leader of an elite fighting squad formed by what remains of the human alliance as they face eradication at the hands of the Demon Lord and his army. Kail and his friends do manage to defeat the Demon Lord, but Kail is the only one who survives long enough to deliver the finishing blow; even his talking sword is damaged enough to kill the spirit within. On the verge of death, Kail reaches out to an artifact that the Demon Lord seemed particularly concerned about...
And awakens four years in the past.
His Doomed Home Town, once wiped out in a Demon attack of which he had been the Lone Survivor, is as it once was. Every one of his loved ones are alive and well, and Kail has even been aged down. When he realizes what has happened, Kail resolves to use his knowledge of what is to happen in order to win humanity a more conclusive, less costly victory against the Demon Lord's army. Uniting the forces of humanity about a threat they do not know is coming will be no easy task, especially since Kail's physical strength is no longer what it was when he defeated the Demon Lord. This head start may get him the chance to right the future, but in delving into the backstory of his previous adventure he starts to learn the dark secrets behind his friends' lives and the world.
Both the light novels and manga are published by Alphapolis.
This work contains examples of:
- Animal Motif: Kail is associated with crows, which have black wings like that of the demon lord.
- Awful Truth: Many of Kail's friends from his previous timeline turn out to have had problems in their pasts that he was never aware of that painfully clash with his memories of them. Zentos was responsible for assassinating the princess, Maizar is plotting to use him for his own purposes, Minagi can't handle her money and went off on her own with little experience as an assassin (which to be fair in the original timeline worked out but only due to her natural talent and a TON of luck which is lampshaded in story as irresponsible), Luctera was deathly ill for a long time with a complicated love life involving a dark elf that resulted in a child to boot, and Kail's master and Seren's mother Lelia worships the universe's Goddess of Darkness. Outside of his circle of friends King Remonas, who Kail though was an good ruler, is revealed to have caused most of the problems the human race faced diplomatically, leading up to the demon invasion.
- Bastard Bastard: Prince Calenas.
- Cutting the Knot: The Magic King's Great Labyrinth is full of sophisticated traps of physical and magic types with even more deception magic as you trek further inside and is the only way to access its vault and a magic sword for Kail to continue his adventure, so what does he do? Dig a hole straight to the treasure room and bypassing all the traps. Of course, this is only possible because Kail has already been in the labyrinth so he knows all the answers to questions about the various parts of the labyrinth.
- Divided We Fall: In Kail's original timeline, conflict within the different human nations left them vulnerable and unprepared for the Great Invasion, which caused the fall of both the Zelgius Kingdom and the Galgan Empire.
- Doomed Home Town: Subverted due to Time Travel.
- Double Standard: Abuse, Female on Male: In the early chapters, Riize overreacts to Kail's actions and punches him hard in the stomach, twice. It's played for comedy, like usual in anime and manga. She makes large meals afterward, implied to be a sort of apology; many abusers try to make up for their actions with similar behavior.
- Dungeon Bypass: What Kail and his friends did to get into the Magic King's Great Labyrinth, by digging a hole straight to the treasure room.
- God Is Inept: Chapter 70 has Melra herself speak to Kail through a Willing Channeler, revealing that she's trying to help him save the world from the Great Invasion and instructed her followers to help him. But when he points out she could speak to them about the bigotry and racism they foster, she openly admits while she has nothing against the other races, she can't be bothered to correct them because they're still working on her behalf and haven't tried harming Kail.
- Grey-and-Gray Morality: In the second time line. The politics of the world make it so that royalty, even those who are on Kali's side, try to manipulate circumstances to their favor (up to and including kidnapping and killing those who stand in the way) and Kali himself is more than willing to assassinate people or kill prisoners to ready people for the Great Invasion. On the other end, the Demon faction has basically been divided in two with the current Demon Lord ordering that humans not be killed or attacked wantonly, but some going out of their way to do so.
- Horned Humanoid: The Demons have horns except for the Demon Lord.
- Make It Look Like an Accident: How Princess Mileina death was suppose to be until Kail intervened. This is how the King's death is portrayed as well, thanks to Kail again.
- Men Are the Expendable Gender: All of Kail's friends that turned on him in his new life, forcing him to kill them, are men. While all of the women so far have either been redeemed, or loyal to the cause in the first place.
- New Game+: Pretty much what Kail goes through and lampshaded by the title itself (the original Japanese name of the game mechanic being "tsuyokute new game"). Though it deconstructs this concept in that every change large or small that Kail does drastically alters everyone's lives and the world leaving the "game" with a whole new story and theme.
- Our Angels Are Different: Kali fights an angel as part of his trial for Melra. It's depicted as an armored human with wings and wields a sword capable of erasing what it hits from existence but also appears to lack a soul.
- Our Dragons Are Different: One was powerful enough to challenge the gods. Its heart was the key to turning back time.
- Power Limiter: Seran turns out to be wearing not one but dozens of them, and one said restraining bracelet increases the weight by five times.
- Reality Ensues: Going from a lazy and aloof nobody to suddenly being extremely intent and determined overnight already raises alarms for Kail's friends and family, but they figure it's probably him finally growing up. Going from a guy who was mostly just associated with big figures to becoming a demon-slaying Knight in Shining Armor with a legendary sword that is making waves on the other hand gradually causes every force, human and demon alike, to start setting their sights on him, and while he expected it, he certainly didn't expect the Gray-and-Gray Morality politics that come with it.
- In a certain way, Kail's very New Game+ concept ends up acting as a Deconstruction of the usual idea; his new knowledge applied to a second run is used so drastically that the information becomes more of a handy cheat sheet since he causes massive ripples throughout the coming years, including changes that would've never happened like his mother getting pregnant again due to him leaving home so much earlier. This plus Kail not actually knowing everything thoroughly due to his former suicide squad role and Brilliant, but Lazy attitude in the first timeline significantly limits what he can change, and thus some deaths are inevitable.
- Reasonable Authority Figure: The current Demon Lord in the new timeline is apparently an advocate for improving relations between all races and has ordered their fellow Demons not to indiscriminately slaughter humans. The leader of the Dragons believes that peace might actually be possible because of the Demon Lord, and they were willing to make several concessions to Kail's party.
- Religion of Evil: The worshippers of Melra, the Goddess of Darkness. Not only are they a nasty bigoted bunch they also seem to have a plan that revolves around elevating Kail as a hero for humanity.
- It's later revealed that Melra herself does favor humanity above the other races, but holds no disdain towards the other races. She instructed her worshipers to help Kail to increase the number of people who would survive the Great Invasion, they end up alienating him because of said bigotry. And she doesn't feel like doing anything about that because they are technically working in line with her wishes.
- Royals Who Actually Do Something: Princess Mileina, but not her brother.
- Royal "We": The current Demon Lord speaks in this manner.
- Sacred First Kiss: Kail accidentally takes this from the summoner, Ekses. This is because they were going to form a partial contract so Kail could earn her trust; the contract would keep him from revealing her true name to anyone. In the original timeline, they had made a promise to live through the war and live together in peace; it was essentially an engagement ceremony. Since Ekses kissed him then, he kisses her in the new timeline, under the impression that it's part of the ritual. Her reaction is less than pleased.
- Set Right What Once Went Wrong: The whole premise of the series is Kail traveling back in time to change the future were humanity is practically wiped out. While some of the outcomes for him on his quest may make the final outcome a Bitter Sweet Ending he has made things better for people on a personal level that he's met and improved the conditions of most of the places he's gone.
- Minagi was a cold and aloof assassin in the previous timeline who also had a hand in killing key figures on the pay of political rivals that would have helped against the demon invasion. This was due to leaving home while being lucky and merciless about her own survival. In this timeline she's much more laid back and while still a skilled consummate professional is in a much better place with Kail as her patron/friend and won't end up killing all those people who might have slowed or stopped the demon invasion. Not to mention she's much happier now all around.
- Talking Weapon: Kail's magic sword, Sildonia.
- Time Travel: It's a massively costly form of magic. The only way to get enough mana to go back in time by a few years requires countless human sacrifices, and a one-of-a-kind special magical artifact some believed didn't exist. The Demon Lord easily gained access to the former after conquering human territory, but it hasn't been revealed yet how he got the latter.
- Unwitting Instigator of Doom: Mileina's father chose to protect some human refugees instead of assisting the dwarves in the original timeline, a decision that ultimately weakened the human forces.
- Weapon of X-Slaying: The sword that Seran has was used three hundred years ago to kill a previous Demon Lord. As a result, it has an effect that acts as a bane to demons and can kill them.
- You Have Outlived Your Usefulness: Kail does this towards the king who arranged that the princess' assassination. He also does it to mooks who give him information that he's looking for.