__________________ "Happiness is a lie. Life is horror. The light is always dying all across the universe. The last star will flicker out someday, when it does, all that remains is shadow. And I will be its king!"'-Amahl Farouk
Being above Traya isn't enough to best Nihilus, lmao.
'Thul has zero answers to drain --- meaning --- he will be lose a respectable portion of his Force reserves, the minute the battle begins. Let's also factor in that he is inferior in everything aside from TP, and 'sabers, with the latter not even mattering much here.
You can argue TP, but how well will that work on a Sith essence that is pure instinctual is another discussion entirely.
Yeah, it may depend on TP; I could feasibly see Nihilus being dominated because he's a weak-willed vegetable, but it's also possible that it won't work at all.
Otherwise, this is a pretty good fight. Two novices who have a boatload of strength in the Force'n all. Never can tell where Nihilus is concerned, though, so I won't comment further.
Nihilus is a formidable telepath in his own right. He is able to push visions into other's heads, is cited as having notable Telepathic Influence and Telepathic Visions. Given his power level (multiple planets worth of power), UnuThul's TP isn't going to win the day here.
Additionally being in Nihilus' Aura, UnuThul isn't going to be able to draw on more Force Power than he goes into the fight with, and the sudden feeling is going to shock him long enough to be drained.
I'm not saying multiple at once, I'm saying multiple altogether.
Before he puts his spirit in his armor:
This is pre-Katarr, and that's plural possessive. He had already consumed at least two planets before Katarr, and if we stopped there, Katarr would make it 3 planets total.
In the game Kreia notes this while looking at the Holographic map on the Ebon Hawk with the Disciple:
As common sense, we know there are more than three points to a "web" in an ideological sense. A "string" could be 3-6. but a "web" indicates multiples beyond three.
His power grew with each additional planet he consumed.
There's also TCSWE claiming that Nihilus fed on numerous worlds that he blasted into ruin, although TCSWE does get some information on KotOR II drastically wrong (doesn't mean the entire source is invalid, though).
Historically, draining a victim doesn't mean you add that victim's entire Force power to your own; far from it, in fact. So Nihilus draining several planets does not endow him with multiple planets' worth of power, especially given that there is no constant or set standard for how the Force power of an entire planet. For instance, the Devastation of Katarr no doubt offered far greater yields than Nihilus feeding off some random other planet.