Deep Song vs Obedience

Deep Song
Action, Animalism,

[ani] Bleed with +1 bleed.


[ANI] Frenzy. Enter combat with and lock a vampire. That vampire is considered the acting minion in that combat.

Obedience,
Reaction, Dominate

Only usable when this vampire is about to enter combat with an acting younger vampire.

[dom] Unlock the acting vampire and end the action.
(Do not lock this vampire if they are blocking. )
The acting vampire cannot take the same action this turn.

[DOM] As above, but do not unlock the acting vampire.

Q: A enter combat vs B (B is unlocked) with Deep Song .
B said no block and play Obedience,if that posible or B must lock before play Obedience by Deep Song text?