I have, let's say LE skrull Black Bolt and a Roulette on my team. The enemy has the new Constantine on his team. John Constantine's special attack power--

MYSTICAL WARDS: Other characters can't use Probability Control.

If Black Bolt does a Running Shot/Pulse Wave on Constantine, would this Pulse Wave usage (which would ignor MYSTICAL WARDS) allow my Roulette to use her own Probability Control during this attack?

Thanks....

Assuming Roulette isn't within the PW range herself, sure. Until the ranged combat action that activated PW resolves, Constantine's power is ignored.