Umoqeth, Evaluator

Haste, judge 2 (Whenever this creature attacks,
target opponent reveals the top 2 cards of their library.
You choose 1 of them. Then, they lose life equal to the converted mana cost of the chosen card.)
When Umoqeth, Evaluator enters the battlefield, sacrifice it unless at least 4 life was paid to cast it.
If 6 life was paid to cast Umoqeth, Evaluator,
then Umoqeth, Evaluator deals 6 damage to
target permanent.