"A human has been spotted in Snowdin."
This was it, wasn't it? He could go to Snowdin now and end both wearisome winter and suffocating summer. Or, perhaps, the human would freeze in the snow.
"A human has been spotted in Waterfall."
Asgore could meet them there, but oh, Undyne was so ready and so eager to kill a human. Imagine the glory it would bring her to capture the seventh soul. He couldn't take that from her.
"The human has been spotted in Hotland."
He ought not leave the burden with Alphys; she is no killer, not Hotland is large and maze-like. He could very well miss them. Besides, plenty of Royal Guards patrolled there.
"Your Majesty, the human has been spotted in the Core."
That is a delicate machine; Asgore ought to go down there to stop it, but as he leaves, he catches sight of several castle caretakers huddled around a tv, where Mettaton does battle with the human. It is his first glimpse of them. He watches the battle, and the human is losing. He turns back. He may not have to fight them, but soon he will have to fight someone. Once he is dressed, he waits in the garden for Mettaton.
The door opens, but it is not Mettaton. Asgore stalls, he chatters, he dallies, but he cannot delay the inevitable. When he stands to fight, the human tries to talk him down. Their pleas fall on deaf ears as the first swing of his trident strikes true.