Do not put more than two "Boss" characters in the same tournament. The engine may freeze due to infinite priority loops.
If you want a challenge, the community is famous for creating "broken" bosses. Here are the legendary ones you must face: m.u.g.e.n pc
Have a specific character you want to add but can't find? Check the comments below or join the /r/MUGEN subreddit for download links and creator showcases. Do not put more than two "Boss" characters
Enhance the atmosphere with custom background music for your stages. Performance Requirements for M.U.G.E.N PC m.u.g.e.n pc