i dont think there are rules exactly? it should be something that you think of naturally!! chan is sometimes used for boys when people wanna call them something "cute" or theyre trying to insult you. it makes you sound small or, like, young.
there are definitely waaay too many kanji!! an app like that would even be good for japanese people too, heh.

i understand. supporting me maybe could have made them angry. a betting pool is, gamble? if i know you have done this for my win, i will fight even stronger!! please dont worry about being able to win to me. i use my coaches other players for practice most, and with them i am still the best.