Chaos Mode, a cheat menu, and the whole Resident Evil 5 story as Wesker, Barry, Jill or any Mercenaries character.
How to join the host goes to Play Game → Chapter Select, sets Network Selection to Online, and starts a chapter. The friend opens Play Game → Join Game (or accepts the host's Steam invite) and picks the host's session.
Press F1 in Resident Evil 5 to open the RE5 Chaos overlay. It has three tabs:
Character: play the campaign as a Mercenaries character, and give your AI partner one too. Wesker, Barry, Jill, Josh, Rebecca, Excella and the alternate costumes all use their own models and moves in the story. The change takes effect at the next checkpoint, area or chapter load. Cutscenes still show Chris and Sheva. Characters from the Untold Stories / Gold Edition content appear only if you own it.
Cheats: god mode, infinite ammo, one-hit kills, +100,000 gold, every weapon added to your item box, and a speed slider.
Chaos: turn Chaos Mode on and every 10–120 seconds a random effect hits the chapter: Majini on espresso, bullet time, freeze, turbo legs, giant or tiny Majini, pocket-sized heroes, glass bones, free first aid, paper cuts, armoured Majini, partner swap, bottomless mags. A timer bar at the top shows what's coming and what's running. You can also fire any effect by hand.
Co-op (2 players): in the game's own online co-op, each player picks their own character and the host's Chaos rolls hit both players, as long as both players have RE5 Chaos installed.
Join through the game: the host goes to Play Game → Chapter Select, sets Network Selection to Online, and starts a chapter. The friend opens Play Game → Join Game (or accepts the host's Steam invite) and picks the host's session.
Cheats and Chaos only work in campaign chapters, not in Mercenaries or Versus.
Needs the Steam version of Resident Evil 5 (Gold Edition update). Built on Ultimate ASI Loader; no game files are changed.
Credits: RE5 Chaos by Pitorad, made with Claude Code (MIT). Uses Ultimate ASI Loader by ThirteenAG (MIT), Dear ImGui by Omar Cornut (MIT) and MinHook by Tsuda Kageyu (BSD-2-Clause). Resident Evil 5 © CAPCOM; the mod uses your own copy of the game.