Nilah, The Joy Unbound

Nilah can't be blocked by creatures with less than 3 toughness.

When Nilah attacks, surveil 2. You may cast those cards this turn. If you choose not to cast one or both cards, send them to the graveyard.

Level up (When you've cast 15 cards this game, give Nilah +1/+1 and "When Nilah attacks deal 2 damage to all opponents and creatures your opponents controls.")