NeedsAName
Well-Known Member
IIRC I'm pretty sure that was an unsubstantiated rumor from 2005 or 2006 before Diamond and Pearl came out.the theory that these starters become secondary dark, fighting and psychic typing may be the case because it was originally the type triangle thought of for the actual starters of gen 4 when Game Freak was conceptualizing the game.
They wanted to get away from grass, fire, water to bring it home that this was a tougher, darker region.