Riposte works just fine against people firing- so long as they are next to you. It works against all close attacks, not only melee attacks.
Noit actually possible for you to super-snap an attack on a mook, Christof- your CofC makes your standard mook attacks two frames, and the minimum you can get is one. Your snapped attack rolls evens, which is enough to kill the target. You may indeed Cleave but it will have to wait until after they fire.
Takes you a frame to put away the blaster, Xeth, but of course none to draw the sabre. However, without speed, it takes three frames to move into the fight.
Roan, your snapped attack rolls +2; a rather firm kill!
Sunda, after rather curtly replying "I'm fine, Master," uses Strike to hit at his next target. He rolls +2 for an 11, and that is a kill.
We now have 13 shooters and four targets- three attacks on each; an extra one on Christof.
I have a hit on Roan, for another five damage, and another on Sunda, for four.
And, with a grim inevitability, the fourth wave now comes screaming into the fight.
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CURRENT SITUATION AT: Second Sequence, Frame 5
Boarding area
Xeth: 9/4/4
Roan: 10/14/7
Sunda: 4/18/6
Christof: 8/0/5
Anzat Corsairs x25: 0/5
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Christof may Cleave at once and kill one.
SA, probably not worth it just to wander into this fight- but keep an eye on things.