Mwurboli, Altrar's companion

Mwurboli, Altrar's companion enters the battlefield with five dormant counters on it.
Mwurboli, Altrar's companion can't attack or block as long as it has a dormant counter on it.
Whenever a creature you control dies. Remove a dormant counter from Mwurboli, Altrar's companion. He also receives that creatures abilities and traits.
When Mwurboli, Altrar's companion dies. return all creature cards from your graveyard to your hand.