Sounds cool, but yes, too complicated.It'd be silly and a translation nightmare but Moon Ball being seach your deck for a Pokemon with Moon or Luna or Lunar in its name or attack name or ability name and put it into your hand would be neat, it could grab Clefairy, Cresselia, Ursaluna etc. and they could print more cards around it, probably too much of a hassle though
I would like it to just be a Mysterious Treasure clone but replace Dragon with Dark.