Saying "bad guy" is so relative, though. Doing the right thing the wrong way certainly doesn't make you a bad guy. I didn't think he was a bad guy, maybe just envious. If he was truly evil he wouldn't have stood at God's side.
Did you think Alec Baldwin was a bad guy in Mercury Rising? He's a governmental official who tries killing a little autistic kid, that Bruce Willis protects, because the kid has learned how to break the most cryptic code the government has ever devised. He has to kill one to protect thousands or even millions from the code or kid going into the wrong hands. U see, I don't think inherently he was a bad guy.
EDIT: Oh, and just to let you know, he wasn't trying to start a 2nd War in heaven. The 2nd war (I think the 1st war was when lucifer fell from God's grace and began to rule Hell) had been going on for thousands of years and had reached a stalemate. They were still battling it out, though. Because of this war, no human who dies has been able to transcend to Heaven. What he wanted to do was take the soul of a military expert back to heaven to be the general for the army of angels, who will turn the tide once more to their favor.