I was wondering last week whether or not housing the entirety of the Nova Force might be starting to have an adverse effect on Rich. As Rich noted when he received all the Nova Force, it's happened before, with the giant looney known as Super-Nova, who I remember seeing in an issue of Simonson's Avengers. Wow, I'm all about callbacks to Simonson's stuff these last couple days.
I'm not sure how long it took Super-Nova to go over the edge, but it doesn't to have been very long. Of course, the Worldmind wasn't helping him cope with power like it is with Rich, so we could expect Rich to resist psychological damage for a bit longer. The thing is though, it has to have been awhile since he got all that power. I don't have the issues in front of me, but Rich received the Nova Force within the first couple of weeks after the Annihilation Wave entered the universe, and he didn't rip Annihilus' innards out until over 200 days into the battle, so that's at least six months. Then he spent a couple months resting up, then there's everything that's happened in his series, which from the time he reached Earth to the time he got to Obrucen had to be around a month or so, so it's going on a year, I'd think.
And since Warlock cured Rich of the Phalanx infection, he's been more aggressive. It could just be Rich's natural hotheadedness showing through, but he seems more confrontational, more determined to not back down. When he first started fighting the Technarch, all he was doing was trying to stall it, because he recognized he was outclassed. Once he thought it had killed Tyro, he starts talking about killing it. On Obrucen, when he's not lecturing the heads of state on their lack of concern for their non-wealthy citizens, he's promising that he can save everyone, that he's not going to tolerate any murderers, and now he's going to try and make Galactus listen to his demands, somehow.
When he was on Earth, even though he didn't seem real enamored with the post-Civil War state of things, he wasn't nearly as openly contemptuous of Stark as he has been of Obrucen's leaders. He was still clearly not impressed with this better way of doing things Iron man helped bring about, but he stuck to taking shots at him veiled as comparisons to the more serious situations he'd been embroiled in. When he answered the initial Kree distress call and was met by lots of Sentries, he was willing to fall back and get help, rather than attempt to bull through the entire Kree military.
It might not be the Nova Force, though. It might be that Rich has simply seen so much death these last few years (our time), that he's not willing to accept any more. Stubborn as he often is, I could see that. He figures he has all this power, he ought to be able to do most anything he sets his mind to. Which can still be a bad thing, since it's the same basic problem that came up with Willow in Buffy Season 6 (I didn't buy that it was the magic that was bad. She liked having power because it gave her control. More power = more control.), and that nearly got the world destroyed. In fact, if it's just Rich's natural tendencies causing it, that could be worse. The effects of the Nova Force could be diminished by actually storing it somewhere else. Can't really do that with a person's stubborn streak.
I do like that Rich is stubborn, for the record. It's usually a lot of fun to see a character steadfastly refusing to back down in the face of long odds, even if they can't always win out.