So amazing. I love the colors and the intensity of the whole scene. I also remember one significant little gnome warlock saying those same words from the title right before he summons his own demise in the form of a pissed of Eredar. (talking about World of Warcraft here ^^)
Like I said before I think your work is improving in these couple of posts man. I saw you wanted a critique on this and usually your other pieces so hopefully I can give you some tips.
You know one thing I noticed in your work is sometimes you use solid blacks in big spots. It's perfectly fine to use black but when you use it in a pretty big spot it does sometimes flatten out the piece. You got dashes of purple I see in those dark spots which is pretty good but I think if you work those in more it might help it more and maybe throw in darks that aren't absolutely black but close to it. I say take a good look at artists like Albert Bierstadt. I know it's not sci-fi stuff but you'll get a idea how to handle certain values more in different scenario's .
If I would have any other suggestion and I think your already starting to do this is get in there more with softer brushes to ease some of those stronger strokes in your paintings to blend it more. I think with more natural environments like this one you could maybe just blend slightly more. Think about effects also. With Lava you could get more glows in there...maybe some sparks or chunks of lava spitting out in some areas just to pull the viewers in more.
Hope you don't mind here is a very slight paintover. Mine is on top. In anycase hope that helps and keep up the solid work and keep pushing yourself. Your moving in the right direction man. [link]