The splatter to the right draws away from the focal.
The liquified render in the back is fine, except for that spot where there isn't any dust/smoke (whatever it is

). You should have removed at least some of it.
The red on the bottom right of the render seems a bit out of place with the rest of your color scheme.
I tried to make something with this render a while ago and found it hard to work with because those yellow lines on his arm really draw away from the focal. Maybe dim them down a bit (at the very least)
Maybe add some better flow that goes around the knife.
(Your not rusty from taking a 3 week break /facepalm) Keep practicing and it doesn't matter what type of GFX you are doing, just do something and you will learn much young padawon.