You realize that something is seriously wrong when your opponent in the late game has only 1 last card in his hand, "Gagagabolt". Then he shuffles it back into the deck, picks up the correct monster and starts a really long combo..
This is why Ptolemy needs to be at Limited 2 too. So Onomat deck can't play it with Sister and Head, so their come-back play with just 1 card in hand would not too easily turn the table over.