>>96008954
I don't know about "most evil," but man, I hate how his overall character has been dragged through the mud over the years.

15-ish years ago the Emperor was basically a Paul Atredies type character. A guy who did evil things and allowed evil things to happen in order to (supposedly) prepare humanity for a happier fate far off in the future. It's never outright stated that that is how he was, but being forced to play 4D chess with literal gods and being able to see the future would at least somewhat justify and make sense of his actions.

Over the last few years though, writers just turned him into a petty idiot. He needlessly antagonizes his demi-god sons, gets all his best ideas from someone else, and then when Guilliman yells at him in whatever book it was (after Guilliman has woken up after 10,000 years) about why the Emperor even bothers continuing to serve humanity even while he has clear contempt for them, the Emp's response is literally:

"Lol, I dunno. Only in death does duty end so I guess I'm not dead even though I hate everyone I guess I'll keep staying alive and pushing humanity on. Lol."