Uaan Vek The Seer

When you cast Uaan Vek choose one of the
following
Creature: Uaan Vek becomes an 8/8 with
hexproof and has the following pay {x}
then grant all Abyssal +X/+X
and hexproof until end of turn
Sacrifice: Look the target opponents hand/library
and select the top 5 cards and exile them