Harry Potter, Boy Who Lived

Trample
Whenever Harry Potter, Boy Who Lived deals
combat damage to a player, as you cast spells from
your hand this turn, they gain cascade.
(When you cast this spell, exile cards from the top of
your library until you exile a nonland card whose mana value is less than this spell's mana
value. You may cast that card without paying its mana
cost if the resulting spell's mana value is less than
this spell's mana value.)