Korosu means to kill in Japanese — and the game earns the name. A dark revenge story inspired by Kill Bill, set across a criminal-overrun Sevii Islands and a ruined Kanto. You start with Gastly. You can kill trainers. The Elite Four is replaced by a 64-trainer tournament. Nothing here plays like a standard Pokémon game — and that is exactly the point.
The most daring original story in GBA ROM hack history — and winner of Best Storyline at the 2016 PokéCommunity Hack Awards.
Pokémon Korosu is a completed FireRed GBA ROM hack by Crizzle, the creator of Pokémon Outlaw and Pokémon CAWPS. Where his earlier work leaned on absurd humour, Korosu is a deliberate tonal shift — darker, more serious, and more narratively ambitious than almost anything else in the GBA ROM hack space.
The name says it all: Korosu (殺す) is Japanese for "to kill." The game was inspired by Kill Bill and it builds around a revenge narrative that puts character motivation and story stakes ahead of the usual Pokémon gym-badge formula. It won Best Storyline at the 2016 PokéCommunity Hack Awards — a rare achievement for a hack this tonally unusual.
Pokémon Korosu contains depictions of violence, human trafficking, mature language including profanity, and the option to kill trainers in some battles. Crizzle rates this T to M equivalent. Not appropriate for younger players. You have been warned — and honestly, that's part of why people seek it out.
A revenge arc that starts with tragedy and ends with a 64-trainer tournament.
The game takes place over a decade after the events of Pokémon Outlaw. A young woman's family is murdered by a powerful mafia-like criminal organisation, and she is taken into human slavery. She escapes — with some help — and sets out on a quest to destroy every person responsible for ruining her life.
The journey takes place across two transformed regions. Part one: the Sevii Islands, now nearly completely controlled by rival criminal gangs of varying strength. The paradise is gone — these islands have become unstable, lawless, and extremely dangerous. Part two: Kanto, left in a grim, broken condition following the events of Pokémon Outlaw. This is not the cheerful Kanto of FireRed. Crime, corruption, and decay are everywhere.
Crizzle has been upfront that Korosu is partially inspired by Kill Bill — a revenge story following a woman wronged by a criminal organisation, working her way up through a series of increasingly dangerous targets.
You do not need to play Pokémon Outlaw first — the game recaps relevant events. But playing Outlaw adds context to Kanto's ruined state and makes many story references land harder.
Every notable difference from standard FireRed — and there are many.
No Elite Four. No Pokémon League. Just a brutal single-elimination bracket at the end of everything.
One of Korosu's most distinctive design choices is replacing the traditional Elite Four and Pokémon League entirely with a 64-trainer single-elimination tournament. Crizzle designed it as a direct homage to the American college basketball March Madness format — 64 trainers, bracket structure, and a climactic finale that feels nothing like the usual Pokémon endgame.
Short answer: no. Better answer: playing Outlaw first makes Korosu significantly richer.
Crizzle's three ROM hacks — Pokémon CAWPS, Pokémon Outlaw, and Pokémon Korosu — all exist in the same messed-up version of the Pokémon world. Outlaw and Korosu share a direct narrative connection: the ruined state of Kanto in Korosu is a direct consequence of events in Outlaw.
Crizzle includes a recap of the relevant Outlaw events at the start of Korosu specifically so players do not have to suffer through (or enjoy) Outlaw just to follow the story. But if you enjoy this style of unhinged, dark, adult-oriented Pokémon storytelling, playing the Outlaw trilogy in order — CAWPS → Outlaw → Korosu — gives the full picture and makes the world-building land much harder.
Practical notes for going in prepared.
Everything you need before jumping in.
Pokémon Korosu is a completed GBA ROM hack of Pokémon FireRed by Crizzle, released in 2016. Inspired by Kill Bill, it follows a young woman seeking revenge after her family is murdered and she escapes human trafficking. The game spans a criminal-controlled Sevii Islands and a ruined Kanto, features Gastly as the only starter, and replaces the Elite Four with a 64-trainer bracket tournament. It won Best Storyline at the 2016 PokéCommunity Hack Awards.
Korosu (殺す) is Japanese for "to kill." The title reflects the game's revenge-driven story, its unusually dark tone, and the fact that it is the only Pokémon ROM hack where killing is a genuine narrative mechanic.
Gastly is your one and only starter. There is no choice of three — the game gives you Gastly and that's it. It fits the tone perfectly for a ghost-of-revenge story set in a dark world.
No — Korosu recaps the relevant Outlaw events at the start so you can follow the story without it. However, playing Outlaw first adds significant context to Kanto's broken state and makes many story moments hit harder. The recommended order for the full Crizzle experience is CAWPS → Outlaw → Korosu.
Yes — some battles give you an in-game choice to kill the trainer after defeating them. This plays out as a black screen with text, not graphic visuals. It has no mechanical gameplay effect but it is a real narrative choice the game presents to you.
Yes. The final updated version was released in 2017. The game is fully completable from start to finish.
A 64-trainer single-elimination tournament, inspired by the American college basketball March Madness format. It serves as the game's climactic finale and ties into the revenge storyline's resolution.
The difficulty spikes significantly in the early game — Crizzle warns players about this in the game itself. You are put in a genuinely tough spot from the start. Later sections vary, but overall it is harder than base FireRed, especially without the safety net of a flexible starter choice.
Other dark, adult-toned, and story-heavy ROM hacks worth trying alongside Korosu.