Matt is not the only one relieved (at Himeka's survival, specifically; from the little they've spoken he still considers Abel to have all Fandaniel's madness and none of the jibbering clown's utility), and on this end at least there is no guilt to it. Perhaps that's foolishness - Meteion's warned him more than once about the perils of courting disfavour, but as he'd said to her then, he's disinclined to take advice on loyalty from a traitor (though the fact he's still talking to said traitor at all probably speaks volumes).

Of course, Matt likely doesn't know any of that.

"Given the stakes if they lose? I imagine they considered the danger an acceptable risk, to wield so potent a weapon against us."