During the entire space journey, only Sans' undeads were killed, he is not that depressed losing some expendable soldiers but the ones that are controlling the spaceships are precious as training them takes a lot of time and resources.
Losing them in such a battle is considered a waste, after all, compared to the incoming great war, the current battle can only be called small skirmishes.
Sans can sense that the main ship is now moving towards a certain direction and his expression hardens.
He knows that this signifies a ship or a couple of them in trouble, he might not be able to become World Destroyer but this does not mean that his strength is now not considered horrifying.
He summons his Natal Weapons and starts spinning with all of his strength, together with the gravitational power of his black hole, he pulls all the nearby objects towards him.