Oh dear.
Basically, I like writing larger characters for this wacky worlds.
Here's Ophinia, who is also super pissed. Basically, she replaces Sans and have a big fancy fight (you'll learn later) and at the end, offers a no-consequence chance to spare her. Not for you, but for HER sake. Since you're on a genocide run, you're likely to kill her.
At the end, you learn how to find her BEFORE getting here, and if you didn't spare her, you find out the ONE thing that choice affects.
Namely, she cuts the jokes and just goes to laser-beaming the shit out of you.
Hope your happy.
Murderer.

Side notes: The thing in her other hand is her Halberd, which is her 'usual' weapon. The idea is that this laser cannon is a lot less forgiving.

Attacks:

• DIE: Big beam, randomly assigned safespot. Think fast.
• TAKE COVER: Beam swipes from side to side. Cover appears. Later in the fight, the cover moves.
• SHOWS SIGNS OF MERCY: Can ACT next turn with effect.
• DESTRUCTOR BEAM: Splits into beams, a pretty fractal effect.
• HACK AND SLASH: Similar to her regular fight, but faster and with a lot of different colours mixed in.

ACT:
(responds with anger unless she shows signs of mercy)

• Check: ??? Att, ??? Def; a really angry bird. Seems that decision DID have an effect after all!
• Talk: Calms down, slowing down the next attack.
• Apologise: after three uses, becomes "apologise profusely".
• Apologise profusely: basically, she stops attacking. Do this three times and she can be spared after a short bullet hell.
• Persist: makes her vulnerable to dying, forever locks out ACT options.
• Beg: Cancels her next attack, and allows another ACT.
• Trick: Next attack works backwards, dangerous, but also has a HUGE affect (she loves tricks). If you attack after using this, you cannot use any ACT afterwards until a reset.

Basically, you need to apologise and talk her out of it. She then kills herself, insisting she had enough. Being not-a-monster, her body and soul persists, and she insists that she's "waiting to catch a bus". If killed in combat, she explodes, killing the player, though she does not respawn upon a load.