After browsing my hard drive i found rogue survivor on it and decided to play it, during that i found something interesing.
In rogue survivor you can reincarnate as other characters like your killer or random npc, when you reincarnate you can still find your body.
With proper skills you can revive other npc with medkit but something happens when you revive your old body, there is a bug that you will start to controll both characters at once (or even more!).
You can use that to controll few characters at one time or play hot seat multiplayer with friend!
But be warned! Reincarnation pool is connected to both characters, if one character dies he must reincarnate and if its out of reincarnations its game over for all player controled characters.
Not to mention that game was never meant for multiplayer/multiple player characters at once, so bugs will be there!