Okay, today I decided to continue an old game save I had. I had started a new game sometime in January I guess, so I can't remember much about all the stuff I've done. But apparently, I've taken the evil path, slaughtered all of Stillwater among some other nasty stuff, etc. Anyway, I talked to K'an Hua, he told me to retrieve the Vendigroth device and bring it to him in Ring of Brodgar, so that he can destroy it. I'm now near the ring, but I want to ask something first before I move on.

If I give the Vendigroth device to him and he destroys it, is there any possible way to beat Kerghan anymore, thus it's determined already at this point that I'm going to receive the ultimate baddy ending? Even though I've gone the evil route, I'd like to receive the good ending and kill Kerghan and not join him and kill all my crew. So, should I just lie to Hua? And tell him I already smacked the thing into pieces, when I didn't?

I've beaten the game a couple of times in the past, but I never went the evil path before. I don't want to do something that ruins everything for anyone, so that's why I'm asking.

I haven't completed my evil playthrough yet, but there is one other way of killing Kerghan. You can use the sword whose name I forget (Kyrggard's Falchion?) that's found in the Void. That being said, the implication is probably that you're supposed to buddy up with Kerghan but yeah, you could use the falchion.

Thanks. I decided to go on a limb, since I remembered the Void not being that huge anyway, so it's not like I would've wasted too much time in either case.

Anyway, I lied to Hua and told him I had already destroyed the Vendigroth device, while it was still bulging from my pockets good as new. Then proceeded with the end game as if I was playing a good guy playthrough. Eh...almost, at least, because Arronax was never released from his prison. I couldn't remember how to do that. But, I convinced Kerghan to abandon his plans of Armageddon, although for some reason the game still made me fight him. Weird.

Anyway, as it is usually the case with RPGs, I think I liked the evil playthrough more than the good playthrough. The best thing being that I never had to visit Tulla. I never liked that place. Not to mention, the better followers were evil-orientated. Screw Magnus and the lot, Kraka-Tur and Bane will not stop hitting the enemy until it has fallen!

Plus Torian. Torian is awesome.

I find it hilarious that you can lie to Hua about the device. The thing's like half the size of a human. Where does it go?

Oh, and to free Arronax you have to kill the spirit snake thingy outside of his room.

EDIT: And yeah, Tulla's a pain. Though not visiting it means an evil Mage will always be a bit worse than a good one.

My first playthrough was also as a giant army, it's definitely a lot of fun. Easy (especially with Dog who is a murder machine), but fun. Plus 20 Charisma gives one of the better Perks, so there's that.
I believe the guys you recruit in the Void don't actually count towards your companion limit, though the Gorgoth thing is pretty weird.