Why does Asgore destroy the Mercy button?

The rightmost command is still there when Asgore says goodbye. Then his trident comes down. The menu comes back with FIGHT, ACT, and ITEM, and a blank space where MERCY used to be.

“ASGORE attacks!” The combat menu after the strike. Original game footage by Hawlo, 01:16. © Toby Fox. Image source ↗

Asgore destroys MERCY to make the human fight him. At the barrier, that means going through with the plan he offered his people: collect the human SOULs needed to free the monsters. The strike tells us what he is prepared to do at the start of the battle. What he wants for himself is harder to read. The best clue comes when the button returns.

The empty container

Six SOULs rise behind Asgore before the battle, alongside an empty container. Put that next to his farewell and the trident swing has a clear purpose. He is facing the human whose SOUL could fill that last space. You can use ACT to ask him to stop, but you still have to fight to get past this encounter on the Neutral Route.

Once Asgore is on his knees, he explains what his declaration of war did for a kingdom that had lost hope. He also tells the human what it cost him. His wife left, and he is tired of hurting people. He asks the human to take his SOUL and leave. In that moment he offers a way through the barrier that would cost him his life.

MERCY comes back cracked

The choice now appears inside the battle box. FIGHT is on the left and a cracked MERCY is on the right. It looks like the button from the opening, but the choice is no longer about getting out of an active fight. The fight is over. The human gets to decide what to do with the person who started it.

The cracked command in the post-battle choice. Original game footage by Hawlo, 06:59. © Toby Fox. Image source ↗

Did Asgore destroy the button because he believed he deserved to die? His request after losing makes that reading understandable. Watch what he does when the human actually spares him, though. He is surprised that they would stay underground, and he starts picturing a life with them. His thoughts go straight to the living room, stories, and pie. A man who has just offered to die can still imagine accepting mercy. His response leaves room for guilt without turning it into a settled plan he had before the fight.

Sparing Asgore and saving him

In the first Neutral ending, choosing MERCY means the human lets him live. Flowey then attacks Asgore and destroys his SOUL. The button worked. Flowey acted on his own.

A later Neutral branch lets that pause go on for longer. After the same choice, Asgore begins imagining a family and then calls it a fantasy. He comes back to the problem of getting the human through the barrier and chooses to give up his SOUL himself. Flowey appears afterward. The Undertale Wiki’s battle entry describes this as a conditional branch after a previous Neutral completion. The number of times you have fought Asgore is an incomplete guide to which scene you will see.

The opening takes away the option to spare Asgore. The ending restores the option without giving the human control over Asgore or Flowey. The crack is a reminder of what the human had to do to get that choice back. What happens after they make it depends on someone else.

Scenes cited

• The barrier and Asgore’s Neutral battle · English game footage by Hawlo. The opening strike is near 01:05 and the cracked button appears near 06:59.
• A later Neutral branch after choosing MERCY · English game footage by Arctic Foxy. The choice is at 06:22 and the speech diverges around 07:08.
• Why does Flowey show emotions without a SOUL? · A closer look at a different set of scenes about Flowey and compassion.