Murder Time Trio+

Dust/Murder+ having enough of his guilt and distanced himself completely from his dusttale destroying it and killing any and all versions of dust and murder sans that exist.
Killer+ realizing the only good ending he experienced was utterly fake and would keep being corrupted by chara or being controlled by nightmare completely snapped his soul transitioning into phase 4 he began to assasinate every killer sans that exists and doesn't exist.
Horror+ after experiencing trillions of aliza's reruns made him think back to the events of the villains sans squad event. That's when he realized countless other versions of himself existed meaning infinite horror tale timelines and infinite copies of the horrortale universe. Horror than began making a machine that drained the remaining magic from both monsters, the underground and the barrier this gave him the magic and LV necessary to travel to them and consume all of their residents. Horror+ was happy he never would go hungry again.
Insanity+ Grew bored after the player had given up on this world and there wasn't any other monsters or anything else to kill for that matter. Eventually insanity's IQ came back and he realized what could quell his boredom he started to take more determination drugs. Not only did he upgrade this determination drug to bring all his lower attributes up to the level of his higher ones but he kept getting stronger and stronger but eventually the determination extracted from the 6 human souls no longer granting him and meaningful increase at this point. So he began experimenting with his teleportation and ended up in other undertale:insanity timelines killing both the insanity sans and absorbing the soul of each determination soul of player. Eventually he did this too all universes and timelines with one to this very day.
And a 5th unknown individual.
Their opponent? Harmony!Chara/Corruption!Chara from the godverse.