Sans douges Gaster's attack. He looks at his soul. It's slowly turning black. Chara is corrupting him. Sans ACTS. He checks Gaster.

W.D. Gaster. 666666 atk, 666666 def. Cares about nothing other than helping himself and I survive the reset. Has grown very powerful with the human souls he just gathered. Give up Sans, you're mine.

Gaster attacks again with Gaster Blasters. Sans douges. He feels his sins weighing him down, slowing him. He remembers the people he's killed. He thinks about the child he killed to get the first soul. They were just a softmore, and Sans had killed them in cold blood. Sans remembers the Froggit he killed, an innocent monster, dead. All because Sans didn't want to pay for his sins. He remembers killing Frisk over and over and over again. He remembers dunking the kid when they offered him sincere MERCY. Sparing them could have stopped Chara, but he dunked them out of a selfish desire for vengeance.

Sans collapses under the weight of his sins. Gaster grins, "heavy, isn't it? Don't worry son, this reset will be over soon." Gaster attacks, dealing 999999 damage... to Grilby. Grilby reignites.

"Are you OK?" Grilby asks.

"I'm OK," Sans replies.

"Good," Grilby smiles, "you save yourself. Go have Frisk reset."

"How do you know about the resets?" Sans asks.

"You mumble in your sleep," Grilby explains, "something about Frisk and timelines. I finally put the pieces together a year ago. I've known for a while Sans. Now, go. I'll handle Gaster." Sans is about to flee, but hesitates. "Listen," he explains, "I know now's not a good time to say this, but thank you. You've always been there for me and Papayrus. You've always been like a Father to me."

Grilby smiles, "I'm always here for you and your brother, and I always will be." Grilby hugs Sans. Sans uses MERCY to flee. Grilby's soul turns green.

"Now you've done it," Gaster growls, "I can't afford any distractions. You should've stayed as cinders Grilby, but now, I'm going to kill you."

Grilby FIGHTS. Gaster douges. "You may have taught Sans how to dunk," Gaster grins, "but I taught him how to douge."

Gaster FIGHTS. Grilby goes out and reignites.

"You were never there at any other time," Grilby replies, "you turned your son into a weapon. Raised him to kill humans."

"I raised him to survive!" Gaster replies, "I raised him so he could protect himself!" Gaster FIGHTS. Grilby goes out and reignites.

"You raised a weapon," Grilby replies, "I raised a son." Grilby FIGHTS, but Gaster douges again.

Gaster realizes he can't defeat Grilby through conventional means. He checks his ACT menu. He can: douse or check. He checks Grilby.

Grilby. 20atk 20def. Made of fire, maybe you can put him out...

"You don't get it," Gaster growls, "humans are dangerous, but Sans can defend himself, the underground, everyone. We need someone who could defeat humans. Sans was our best hope. I had hoped you'd stay with our agreement, but you decided it'd be better to wait for a seventh human. Sans could have taken the souls and crossed the barrier. He could have gotten the last soul, by force of necessary. Why didn't you finish the plan?!?"

"He was only a child!" Grilby replies, "I couldn't put such a burden on him at such a young age. I couldn't force him to FIGHT. Enough of this Gaster. I won't let you hurt Sans, my son. Die!" Grilby FIGHTS with all his might. He manages to hit Gaster... dealing only one damage.

Gaster ACTS and douses Grilby. Grilby is doused for good. His glasses fall to the ground. Gaster checks them.

Grilby's Glasses. O def. Grants the ability to dunk. Gaster puts on the glasses. They could be useful if someone offers him MERCY. He takes a shortcut to the surface.

Meanwhile, Sans takes a shortcut to Frisk's house. "Don't do this," Chara pleads, "you'll lose everything you've worked so hard for."

Sans knocks on the door. Frisk answer. "Frisk," Sans explains, "you need to reset. NOW!"