It's a fairly nice effect but would probably be better if 1)The plasma pistol and AR weren't in the background. 2)The spartan wasn't looking down and firing his laser... maybe you should have had someone else do that to you, maybe from the back. Is the red stuff flying out bloog? I'm not a big fan of H3 blood, but that looks pretty sweet.
The "redstuff" is actually the spartan lasers impact on the ground, and I agree with everything you said.
It wouldn't make a difference if he was invisible because when he fired the laser he wouldn't be. The laser would have to be fired from derectly behind the spartan so you couldn't see the laser or the person firing the laser. The pose kinda ruins it because he's looking down and you can't see much of his face. Having a guy behind him shooting the laser would fix that. Also, I think it would be better if the camera was closer to the spartan.