base set pokemon card box TCG: Mega Evolution each with 10 cards Pokemon Scarlet & Violet -

If the revealed card is not a permanent card, it remains on top of that library

However, you can't put five cards from your graveyard on the bottom of your library and one card from your opponent's graveyard on the bottom of their library.

Leaks and official teases by way of The Pokmon Company International as well as Japanese releases have already confirmed several major Mega Evolutions in this set, including: Mega Mewtwo X Mega Mewtwo Y Mega Lucario Mega Banette These four are expected to headline the English set, which will likely pull directly from the Japanese Night Wanderer expansion

So Crumble to Dust is fine