Action modifiers played by other minions while acting out of turn

I have two minions:
Minion A is untapped and has an untapped Enkil Cog.
Minion B is untapped and has Obfuscate.

It's the end of someone else's minion phase. I tap Enkil Cog to take an action with A. Someone tries to block.

Question: Can minion B play Veil the Legions to grant stealth to minion A when it's not my turn?

(I thought there was no rule that would prevent it, but I was outvoted by other players who said it wasn't legal.)


Card texts:

Name: Veil the Legions
Cardtype: Action Modifier
Discipline: Obfuscate
[obf] Only usable by a ready, untapped vampire other than the acting minion you control. The acting minion gets +1 stealth. Only one Veil the Legions may be played each action.
[OBF] As above, and this vampire may burn X additional blood to give +1 stealth to the next X actions your minions perform this turn. Only one Veil the Legions can be played at superior each turn.

Name: Enkil Cog
Cardtype: Action Modifier
Requires a vampire of capacity 10 or more. Unique.
Only usable when this vampire successfully bleeds your prey (play after resolution). Put this card on this vampire. During any Methuselah's minion phase, this vampire may tap this card to attempt an action. This vampire has +1 bleed.

You can play Veil the Legions on your Madness Network/Enkil Cog/Anjou action. [LSJ 19970630] .