Sans/Underdeal

File.DealSans.exe is a god-like entity with the power of the 7 human souls and almost all of the underground. He has the appearance of a normal Sans, wearing a black hoodie with a big, glowing USB symbol on each sleeve, 2 on the back and 1 going straight down the front. He also wears a sash across his chest with vials of all different colours, like the the one Ink!Sans has. Both his eyes glow, instead of just one, and the the colour constantly changing between the colours of the 7 souls.
His story is pretty similar to Dust!Sans' story. He started going insane from genocide runs and finally escaping to the surface, only to wake up back in the underground. He formed a plan to change the course of the story....Permanently. He warned Papyrus and king Asgore of Frisk, so by the time Frisk was back at the beginning, everyone was already taking shelter at the castle. Sans just needed a few more pieces put in place to pull this off. He convinced Flowey to make sure everything went properly for Frisk, and to extract some determination from them to get the next piece. After getting the determination, he used it to power the machine in his hidden lab and bring back Gaster. Once Gaster was free, he gathered everyone he needed to put the plan into action. He, Gaster, Flowey and Papyrus met Frisk in the judgment hall with the 6 human souls. He had Flowey take Frisk's soul and Gaster separated Chara and Frisk, with their own separate souls and kept the one he took. Sans absorbed the souls and all the other monsters soul to become a god.
Sans finally got what worked hard for, the end of the resets. Sans thought it was over, but it was far from that. With the power of all the souls, he could see things others couldn't, all the AUs and the Sanses in them, as if if he was seeing through their eyes. Then he saw it. A Sans that was corrupt, glitched, broken and dangerous, known as EXE, coming for them. He couldn't leave everyone there to die, but their souls strong enough to exist in an anti-void. He wanted to at least say goodbye to Papyrus, but when he extended his arm to hug his brother, his left hand started glowing and a black cloud surrounded it. Papyrus reached over and grabbed his hand to see if he was okay, but when he touched it, Papyrus' soul came out of his chest and an orange string shot out of Sans' hand, that warped around Papyrus' soul. Papyrus' battle body suddenly turned black and red and covered more of his body, a hood extended from it and went over his head, and and long bone appeared in his hand. Sans saw his brother's soul suddenly became immensely more powerful, which meant he could survive in an anti-void. He went over to Gaster and did the same thing as before. The same thing happened, only with a black string. Gaster's coat morphed into a cloak with a hood and a purple crystal on the back, and purple light filled in the holes in his hands. For every one of them, Sans enhanced their souls, even Chara. Frisk got a black hoodie, teleportation and telekinesis, but most of his features stayed the same. Chara got a black body suit, a black hoodie, red highlights in her hair and a sword that could slice through reality. Flowey could change between Flowey and Asriel at will. As Flowey, his petals became black and received an artificial soul. 
(I will add more when I can. sry)