Given that Light's current opinion of him is that he's a selfish but talented guy who can at least be incentivised to do the right thing, she's not going to lose any sleep over it. She watches him for those initial strikes, until she's confirmed that he knows what he's doing, and then turns away to launch another barrage of ice and fire at a writhing mass of seasnakes.

She snorts at his boast, though.

"These aren't big enough for you?"