Tiamatheus

Flash, Flying, Vigilance, Trample
When Tiamatheus enters the battlefield, you may reveal a dragon creature card from your hand,
then Tiamatheus deals damage equal to its CMC
to all opponents
Discard a card and pay 5 life, then choose one:
All Dragons have Hexproof until end of turn
All Dragons have Undying until end of turn
All Dragons have Ward 5 until end of turn