Baron Strucker Arrogance and Montesi Formula Mystic Beam.

[Neek]

If Strucker pays for Arrogance before using the Mystic Beam attack, does it only apply to the first target or all the targets? 

If it only hits the first target, is there a window to pay again for arrogance before the subsequent attack rolls?

[Negoldar]

1 hour ago, Neek said:

If Strucker pays for Arrogance before using the Mystic Beam attack, does it only apply to the first target or all the targets? 

If it only hits the first target, is there a window to pay again for arrogance before the subsequent attack rolls?

It is a Reactive superpower that is used during the resolution of an attack. It will apply only to the target you are currently attacking.