Nihilus could sense individuals, he just didn't acknowledge them, as Visas said he noticed stars and planets, not individual persons, not because he couldn't sense them but because a single person didn't have a strong enough connection to the force for Nihilus to give a damn. Otherwise Nihilus sensed individuals, they weren't powerful enough to warrant his attention.
Ok, mind proving that? Prove that he could sense individual being, especially he Visas says he didn't know his ship had been boarded. Now for your argument to be correct, Visas would have had to said "He doesn't CARE that we boarded." She says as plain as day that he doesn't see people only planets and stars. Kreia also mentions it also, now we have me with 2 sources backing me up, and you with an assumption...
And what does this have to do with anything, some argument for Revan against a 1 v 1 confrontation with Nihilus?
Obviously genius, read the damn topic before you post.
Nihilus would tear the force from Revan (and kill him) under such a circumstance,
Thats assuming Revan doesn't simple stay out of range and summon a force storm over his head.