This is based of a sketch I drew several months ago that I never had the guts to digitize… Until now. Except that it originally had Trackhead instead of Glowing Constellations (AKA Orion), this is because I felt that he suited better the situation than Trackhead. Another change is that the background is different.  
In case you ask where the battle takes place, it takes place in an abandoned park where the mecha-hydra threw a fiery rampage that Orion must shoot off shut.  
Last but not least I tried to draw backlit shading, it came out neat on the mech but it’s a little underdone on Orion.