Kyza, Soul of the Pack

Menace, Empower (Whenever this creature attacks
with two or more other creatures, put a +1/+1 counter
on it. It becomes empowered for the rest of the game if
it is not already empowered.)
When Kyza becomes empowered, create a 2/2
Green Wolf creature token.
Whenever Kyza, Soul of the Pack dies, if she was empowered, creatures you control get +1/+1 and
gain menace until end of turn.