Morgan Kills Richard. Morgan Jones snapped!
In Benjamin, he saw a piece of his child.
He saw a chance to have that bond with someone again- someone he could manage, someone he could tutor, someone he could think about.
Richard took everything without end and Morgan Jones couldn’t remain for that.
From the minute that he acknowledged what he’d done, Richard turned into the physical encapsulation of the end of the world and Morgan Jones needed to snuff it out before it could cause more harm.
Furthermore, I figure Morgan Jones could perceive how lost Richard was.
He was eager to forfeit himself to begin a war and wouldn’t fret the way that there would be misfortunes once it began.