Mrsha the Great and Terrible

Mrsha is a Doombringer
{t}: give up to 3 beast +1/+1 until end of turn. Activate this ability only any time you could cast a sorcery
{3}{g/w}{g/w}: Mrsha gains +1/+3 and hexproof until end of turn.
Palt, can you cast [Darkness] on the second floor
for us? Pwease?