The mass discard effect is powerful by itself, but filling the hand with cards that are, by themselves, useless? It would take several turns to recover from that. I feel that this card needs to either cost much more than 10/10/10 or have a condition applied to it. Perhaps it only occurs if the opponent triggered a keyword by filling the token gauge on the last turn? That way, it's punishment for the opponent having likely filled his hand with a certain keyword.
I acknowledge that the card, as proposed, would not discard zero-cost cards, but since zero-cost decks are far from viable, this isn't much of a weakness. I also feel the need to pose the obvious question: What does it do to mixed-cost cards? Then again, if it only affected cards that cost a single resource, that might be enough of a limitation to make it interesting.