Nihilus vs. Abeloth
Since our dear Fuhrer Ush closed this thread do to his inability to follow a conversation and as a way to divert attention from his insecurities, I'm reopening this one with a new twist.
The battle is now in the drag nightclub from "The Birdcage" and instead of weapons, the combatants get glow sticks (rave). Also, Nihilus gets a drag outfit. FIGHT
I've always been a bit unsettled by drag outfits. Frankly, too much makeup on anyone is disturbing in the extreme. Especially in light of those really macabre pictures of Abeloth that the new guy posted a couple months back, I'd give it to her.
In all seriousness, N.'s particular brand of abomination might make him the perfect counter for Abeloth. From the snippets you guys have posted, she appears to be a construct or emanation of the Force itself. N.'s abyssal nature--even before the drain comes into play--puts him on the most appropriate footing for a fight.
Feat-wise, N. has the chops to stand up to a prolonged slugfest with Abeloth. W/r/t skill, he might be undone by the obscure/sideways techniques she uses; this I think is less of a danger because, again, his mind is mostly scrambled (listen to him speak!).
Basically, I'd say N.'s glowstick powers are greater than those of the Elder Evil.