|“||Human, it was nice to meet you. Goodbye.||„|
|~ Asgore bids Frisk farewell before he fights him.|
|“||I remember the day after my son died. The entire Underground was devoid of hope. The future had once again been taken from us by the humans. In a fit of anger, I declared war. I said that I would destroy any human that came here... ...and free us from this terrible prison. Then, I would destroy humanity... and let monsters rule the surface, in peace. Soon the people's hopes returned. My wife, however, became disgusted with my actions. She left this place, never to be seen again. Truthfully... I do not want power. I do nor want to hurt anyone. I just wanted everyone to have hope... I cannot take this any longer. I just want to see my wife. I just want to see my child. Please... Younge one... This war has gone on long enough. You have the power... Take my soul and leave this cursed place.||„|
|~ Asgore to Frisk after being defeated in battle.|
Despite his threatening claims by the other monsters of the Underground to Frisk, Asgore is a kindhearted ruler who loves each and every one of the monsters that live in the Underground. Gerson describes him as a "friendly happy-go-lucky kind of guy", also implying that he is sociable and likes to walk around and talk to people. Asgore seems to freely allow other monsters to visit his home and talk to him about any problems they have, as evidenced by the note he left in New Home. He tries to make the Underground safer for those who enter his realm, as he once released a mandate on puzzles, claiming spikes to be ineffective and hazardous to kids.
Despite his claim to destroy humanity, Asgore knows it may not be the right choice, as he does not want any of his warriors to risk being killed on the battlefield, especially Undyne. During the fight against Frisk, he conceals his face by looking downwards, showing his reluctance to fight back. If Frisk kills him on a Neutral Route, he dies smiling. If Frisk spares him, he will offer to take care of them and suggest that they live together as a family. If Frisk spares Asgore on a second Neutral Route, Asgore will change his mind and decide that Frisk's freedom is what his late son, Asriel, would have wanted, and finishes himself off to free Frisk.
Asgore is known for being rather poor at coming up with names, naming things quite literally, as he found a home for his people and named it "Home." Likewise, when they found a new home, he seemingly named it "New Home". Gerson mentions that Toriel "was really the brains behind the throne", suggesting that Asgore isn't the most intellectual monster.
King Asgore and Queen Toriel ruled the Underground full of monsters for millennia after humans sealed the Underground with a barrier after the war. Toriel and Asgore later had a son, Asriel, and adopted the first human to fall into the Ruins.
Following the accident that led to their children's demise, Asgore, determined to avenge his children, swore to kill every following human who fell into the Underground and collect enough of their SOULs to shatter the barrier and destroy humanity. Toriel, disgusted by Asgore's lust for bloodshed, left him and returned to the ruins.
Before Frisk fell into the Underground, six more children fell into the Underground and died, with Asgore collecting their SOULs for future use.
Asgore meets Frisk inside of his thrown room and offers to show them the barrier. He gives them a chance to turn back if they have anything left to do. Asgore does not mind the delay, admitting that he is not ready either.
As the fight begins, Asgore says it was nice to meet Frisk and destroys the player's Mercy option, forcing the player to use the Fight option to defeat Asgore.
Once Asgore is low on health, he admits defeat and lets Frisk be able to take his SOUL and exit the Underground. Frisk then can decide whether to kill or spare Asgore. If killed, Asgore turns to dust and reveals his SOUL with a smile on his face. If spared, Asgore is amazed that Frisk would remain in the Underground and promises that he and Toriel will take care of them as a happy family. However, regardless of Frisk's decision, Asgore's SOUL is shattered by Flowey, who takes the six souls from Asgore to transform into a God.
If the player spares Asgore on their second run through the Neutral Route after sparing him on the first, Asgore instead insists that the player to take his SOUL and leave the Underground as it was what Asriel would have want, before finishing himself off.
Asgore's death had a grave impact on the monsters. As well as that, the 6 human souls disappeared after Flowey was defeated by Frisk (who returned to The Surface), further dampening their moods. Depending on the Player's choices, either Toriel, Undyne, Papyrus, Mettaton, Alphys or The Annoying Dog (Toby Fox) will take Asgore's place as Ruler, or The Underground will become an uneasy and hopeless anarchy.
True Pacifist Route
When combat with Asgore begins, it is interrupted by Toriel, who hits him just like how she hit Flowey at the beginning of the game. She tells Frisk and Asgore she interrupted their fight to prevent them killing each other to let either of them pass. Asgore is amazed to see her again, but she angrily reminds him how she disliked his plan to collect the SOULs, plus he could've gone through the Barrier after collecting one soul, but instead chose to wait and hope another human never came. After that, Undyne, Alphys, Sans, and Papyrus join in the conversation. Undyne comforts a heartbroken Asgore, who is in tears after Toriel denied that they could even be friends. Papyrus soon reveals that a it is all interrupted by Flowey, who absorbs all of their SOULs to transfer back into his original form, Asriel Dreemurr.
During the fight against Asriel, Asgore, alongside Toriel, appear as Lost Souls that Frisk must save to defeat Asriel. At the end, Asgore, alongside the rest of the main characters, venture outside the broken portal and witness the Sun setting from atop Mount Ebott. Asgore says that it will be the beginning of a new era, in which monsters and humans will live together at peace. He also asks Frisk to be the ambassador of the monsters. During the end credits, he is seen trimming a hedge into the face of Papyrus in front of Toriel's new monster school.
On a side note, this is the only ending in the game where Asgore does not die.
When Frisk/Chara reaches the thrown room after killing Sans, Asgore, who was warned by Flowey of their arrival, doesn't recognize the protagonist as a human, asking them what kind of monster they are. Frisk/Chara initiates combat and instantly depletes Asgore's health bar with 9,999,999,999 damage without any player action. Flowey, showing his "loyal" side to the player, deals the final blow to Asgore and destroys his SOUL, although his plead for mercy is ignored and he too is mercilessly killed.
- His first name is an anagram of the Latin word "Aegros," which can mean troublesome, anxious, sad, difficult, or reluctant.
- Asgore is immune to biologically aging until his child and successor has grown old enough to take his parents' position as the leader of the Underground. However, since Asriel is dead, Asgore is unable to age permanently, therefore immortal.
- Asgore's voice can be heard in the Game Over screen and when the player sleeps in Toriel's home after sparing or killing her. These were his spoken lines to the first child on their deathbed.
- Asgore has a Santa Claus outfit in his bureau, implying that he may be the Santa Claus of the Underground who leaves presents under the tree in Snowdin.