Don't place text in a corner. For text apply rule of thirds!! read them! I do like the "applied" image you did on it though!
Border: black or white or none! This just distracts.
The "wall" kills the depth and kills any flow. This is about a man standing in front of a wall, with some splatters and lightning . Nothing more, nothing less!
Doesn't want to make me look twice at it.
You placed the render out center. that's good! Makes it more "alive"
As DatNoob said: the right side looks a bit "dull"

I don't want to be harsh on you, just things you might consider working on.
keep 'm coming.

XL