Enthrall Symbiote

Shroud
Symbiote creatures you control have "Ferocious —
When this creature attacks, it gets first strike and
+2/+0 if you control a creature with power 4 or greater."
At the start of your turn, for each opponent,
choose one symbiote type permanent they control,
you gain control of it. If Entrall Symbiote leaves
play, return them to their owner's control.