Sans can teleport or stop time which is very dangerous plus the gravity manipulation can move you faster than the speed of sound and he could send you to space so fast with it.
SCP-6969; Euclid; 80x80 room with magnetic-sealed Vibranium doors with absolutely no security cameras; SCP-6783-A is an interesting find. Some days he may give advice, and on other days he is out for blood. When any technology with cameras are in his view, he says "You're gonna have a bad time?" When he says that, his right eye will glow, indicating that you indeed will have a bad time.
He can teleport, summon ghaster blasters, summon bones and crack cringe-worthy puns. That's why a skele-TON of people can find him annoying, and a pain in the ass to beat. His other powers are relatively unknown. STAY AWAY AT ALL COSTS