It was Foretold!

When It was Foretold! enters the battlefield,
secretly choose a number. (And it can't be zero!)
Declare "It was foretold!", reveal the number you
chose: Gain X life, where X is the number you
chose that appeared in an opponent's action.
Return It was Foretold! to your hand. (Actions
include untapping X permanents, drawing X
cards, casting X spells, spending X mana to cast
a spell, making X tokens, attacking with X
creatures, dealing X damage...)