Remove the fear on Darius' Ult and make the ground shake when he executes someone
It seems very nice to have a fear, but thats it. It is just there for nothing. The only time it will be useful if you have 20 hp and you killed your opponent in lane when there is minion around. That's about only its use.
https://www.youtube.com/watch?v=PNXGyB4PG2Q
Or how about we have both of them? You can also remove fear on minion because that does nothing at all.