Mateus, Ruler of Palamecia

When this creature ETBs, you gain control of
target non-commander creature
or planeswalker. Add a L counter
to that card.
{1}{r/w}{r/w} Until the end of turn, creatures and planewalkers you control with L counters gain protection
from their own colours. When this ability activates
and you control five or more permanents with L counters, exile this card and return it to the battlefield transformed.