Sans doesn't even really note Peridot's absence after flinging her away - instead he's straight back to trying to murder Lambert. The dragon somehow manages to scurry out of the way of the bulk of the laser blast, but he is intent on continuing to try, in between having to try to swerve out of the way of shots of fire in return.

He only partly manages. The fire scorches through his bones, and while it is less damaging than it might be to a creature with flesh that could cook and burn, the concussive force behind it still rattles and sends him sprawling. They exchange blows back and forth as Lambert descends, and it's not until they are closer to the ground that Sans loses patience for a batter of ranged fire.

He charges Lambert again, trying to bite down with fangs and tear him off the wall, allowing both of them to plummet to the ground again. This should be over already.