Manuel, Diplomatic Duelist

Ward—gain 5 life
Whenever an opponent gains life, exile the top
card of their library. If it is a nonland card with
mana value less than or equal to the amount of
life they gained, you may cast it without paying
its mana cost. Otherwise, you may play it for as
long as it remains exiled and you may spend
mana as though it were mana of any color to cast
it.