That left side looks pretty good under the text, I can't tell what the focal is for the life of me, and the right side is way too dark so you've lost all your details. Text is eh, might be better on the right side considering it is mostly just black currently and so won't be covering the left side.

Colours are pretty nice though, make the purple elements colder though, more blue.

couldn't agree more with the above. it looks like it might be a sick tag even if you removed much of the right hand side and made the text a little less overpowering.

It's way too dark, there's little detail and the text looks low quality/oversharpened.
I kind of like the effects right of the text though.
You should use them as a basis for your next tag.