About
Onimusha 3: Demon Siege is the third mainline entry in Capcom's Onimusha series, an action-adventure game built around fast melee combat and the signature Issen counter-kill. It moved the series from pre-rendered backdrops to fully 3D real-time environments and split its story across two heroes: samurai Samanosuke Akechi, voiced and modeled on actor Takeshi Kaneshiro, fighting the demonic Genma in modern-day Paris, and French soldier Jacques Blanc, played by Jean Reno, transported back to feudal Japan. Well reviewed as a high point for the series, the 2005 Sourcenext-developed Windows port was later published in the West by Ubisoft and is no longer sold digitally.
Identity
Launch
- Binary
- oni3launcher.exe
- Needs files
- none beyond the binary
Proton
- Version
- GE-Proton
- Winetricks
- —
- ProtonDB
- ProtonDB Gold runs perfectly after tweaks
⚙ Setup notes
Game: 2005 PC port of the 2004 Capcom action game; delisted Steam release (app 6570). Community reports it runs well on Deck.
Launch: Start via oni3launcher.exe — pick 800x600 in the launcher and it auto-scales to the Deck panel.
Display: The community ThirteenAG widescreen fix (dropped next to the exe) adds 16:9 via the oni3_ws.exe entry.
Controller: The on-screen Start button does not register on Deck — map R3 to Start in the Steam Input layout as a workaround. XInput pad support comes from the community OnimushaEnhanced wrapper.
Install: deckport only configures the prefix.
The one thing to know
Runs on Deck: Community reports confirm it runs on Steam Deck (well-behaved with GE-Proton); rate it Deck 'Playable'/Gold.
Controller: Two control caveats — the Start button does not register on Deck, so bind R3 to Start in your Steam Input layout; and native controls are stiff, so XInput pad support relies on the OnimushaEnhanced wrapper (a Steam Input gamepad/keyboard layout also works as a fallback).
Display: Optional ThirteenAG widescreen fix gives 16:9 via oni3_ws.exe.
Proton: Historic Proton versions could show a black window/save crash; GE-Proton is the known-good pick.
Install: Recipe describes setup only.
Get the artwork
deckport never hosts game images. Open this game on SteamGridDB, pick
the cover / hero / logo / icon you like, and drop them into the
game folder under .deckport-art/ before you push it to the
Deck. The importer files them under the right names automatically.
Run it on your Deck
Two files: the one-time importer (deckport.py) in your
Deck's home folder, and this game's install helper. Copy the game
into ~/Games and run the helper with Steam closed — it
writes the recipe (binary, launch options, Proton version)
and registers the shortcut with artwork.