UnderFell Sans

Phase 1
Sans has 4 main attacks in Phase 1, 5 with new attack.

Dual Blasters: 2 blasters shoot at where the mouse clicked on screen

Bone Rush: Bones get sent towards the direction of the clicked area

Bone Zone: Summons a bone zone at the clicked location

Force: Pushed Chara towards any direction

Big Blaster (upgrade): summons a medium size blasters to blast an area

Phase 2
Sans gets an upgraded version of all of his attacks from Phase 1 but cannot regenerate stamina.

Fell Blasters: Sans clicks on screen and 3 blasters show up and blast it

Bone Rush: Many bones get sent towards the direction of the clicked area

Bone Zones: Summon 2 Bone zones in close proximity of each other

Force: Push chara towards the allocated direction

Phase 3
Phase 3 of UnderFell Sans begins by turning the screen dark and when the screen returns a barrage of bones, homing gaster blasters, and large gaster blasters will spontaneously appear. If you manage to survive then UnderFell Sans will be out of stamina and unable to move which will allow you to kill him.