Lham, Scroll of History

Permanents you control can't be exiled and legendary spells you cast can't be countered.
Whenever a permanent you control becomes the target of a spell or ability an opponent controls, reveal the top card of your library. If it's a legendary card, you may draw a card. Otherwise, you gain 3 life.
"Just as Narset taught me, I will reveal this worlds long forgotten history."