Board Thread:Fun and Games/@comment-27524978-20160317154321/@comment-27620479-20160406042814

Yes, we have evidence. Asgore started a second war, in a fit of rage, over the death of Asriel and Chara. A revenge campaign if you like. After the intro.

It is this war, that causes monsters to attack the protagonist for their soul, and because they are human. By collecting seven, Asgore is to assume a godlike form, shatter the barrier, and conquer the surface of the earth, effectively wiping out humanity.

Now, Asgore doesn't want to fight this war, he never wanted to. He declared it because his feelings got the better of him, and kept going because it appealed to most monsters. That is why he waited for the protagonist, instead of going out with the first harvested soul, collecting six more, and breaking the barrier. Also, I think that is why he looks terrified upon meeting the protagonist on the neutral run, and destroys the mercy option when his battle starts. He believes that there is nothing else left, but either him winning and truly going to an all scale battle, dooming humanity or monsterkind depending on how well it goes, or losing and dying.