1: Ninja mod
my suggestion is a ninja mod, with a huge skill tree, for example teleporting, invisibility, all based around sneak attacks.
also add in samari mobs and ninja mobs and make you choose a side, for samari you could have defense buffs, group heals, and heavy attacks though there very slow.
2: Update one of the build your own spaceship mods.
3: Make a addon for origins (forge) that adds characters from minecraft diaries (by Aphmau) and make them OP.
Please leave the link it comments.