I’m not entirely happy with the effects in the last panel – I hope it’s clear enough what Kat is doing there …

… and if not, she’s basically smoking the whole area up to obscure vision and give everyone some room to escape the killbox they were in at that point. Actually pretty quick thinking, you have to give her that.

↓ Transcript
<The bombs explode on the shield bubble and obliterate it in a bright and loud flash>
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<Kat is momentarily knocked out and blacks out for a moment>
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<She slowly regains her senses and hears some faint voices>
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<The voices become recognizable as she gets it back together>
A Thug: That got 'em! The shield is down!
Another Thug: MOVE IN!
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Someone: QUICK! Get the mage before she -
<Katharina has yet to get up and realizes she is about to get swarmed>
Katharina: <panicked> N-no!
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Katharina: NO!!
<She smashes her hands together and casts a spell>
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<A huge amount of fog rushes out from her hands and quickly obscures her, the people behind her and the attackers in front>