I don't recall all the in-game crests and didn't read the other 300 replies, and I doubt mine will be considered, but I'll just write some for fun, because crests are VERY fun.
Shedinja Crest - Gives it an unbreakable but single-use per battle focus sash so that you can actually use it without spending billions of sashes.
Alt Shed - Does that but also adds safety goggle and heavy duty boots. You can only kill it with poison or super effective moves. This would bump it up to around RU, whereas the prior would not move it from PU at all.
Wishiwashi Crest - Heals 25% of its
