Descend 4 — As long as there are four or more permanent cards in your graveyard, Akawalli, the Seething Tower gets +2/+2 and has
trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.).
Descend 8 — As long as there are eight or more permanent cards in your graveyard, Akawalli gets an additional +2/+2 and can't be blocked by more than one creature.