Allvyn, Devourer of All

Flying, deathtouch, hexproof, haste
Whenever a land an opponent controls is tapped
for mana, add one mana of any type that land produced to your mana pool. Until end of turn,
you don't lose this mana from your mana pool as
steps and phases end.
"I am all and all is mine. I've come to take what is
mine." -Allvyn, Devourer of All