Emrys, Sacred Progeny

Flash
Flying, vigilance, deathtouch
When Emrys, Sacred Progeny enters the battlefield, counter target spell.
{5}{c}{c}{c}: Until end of turn, whenever
Emrys, Sacred Progeny deals combat damage
to a player, that player loses the game.
Free will and and the soul of a mortal will
push him far beyond any celestial.