White Fatalis, Last Wyvern

Flying, Deathtouch, Hexproof,
When White Fatalis, Last Wyvern enters the battlefield, search your library for a Wyvern card,
Reveal it and add it to your hand.
Wyvern's Call— When White Fatalis, Last Wyvern attacks, out a creature from your hand onto the battlefield, it enters tapped and attacking,
and it gains "Sacrifice this card at the end of the
next battle step".