I thought about this for a while and wanted to share this with the community...
What do you people think about a Horror version of Sion?
The credit goes to Gomes Brown for drawing this art. The general idea is that Sion would receive a skin that turns his axe into a chainsaw and modify the visual effects of some of his skills.
Chainsaw would rev up during his Q channeling
W would turn his red shield into a darker, sinister shield
E would receive a similar color that fits to his W
Ultimate would remain the way it is, except you hear a chainsaw sound alongside the gong.
This skin would fit ideally into the Nightmare series and if it's too bloody for the general audience Riot could still replace the blood on his chainsaw + outfit and replace it with dirt, oil or rust.