"What!?" you cry. 'What nonsense is this? Of course he's one of the Few. He works sorcery!" Well, since you asked, I'll tell you the reasons I believe Kel may actually not be one of the Few, at least in the traditional sense. Pardon if this subject has already been breached. But here goes:
Evidence for being one of the Few:
1) He works sorcery, and is apparently vulnerable to chorae (salt on his hand after battle of Sakarpus).
Evidence against being one of the Few:
1) He doesn't comment on the Nonman's mark in the prologue to TDTCB. If he could perceive the onta, surely he would have seen this metaphysically fucked up Nonman, not just his mundane appearance, which is all that's described. Even if the Dunyain suppressed all knowledge of sorcery, wouldn't his inborn ability to perceive the onta still have seen the bruise, whether he believed in sorcery or not?
2) When he tells Akka in TWP that he is one of the Few, subsequently leading to the Wathi doll test, it doesn't mean he's telling the truth. He'd been with world-born men long enough by then to be able to use his facial recognition software abilities to determine who was Few and who was not. He could simply have been testing himself (through Akka) to see if he could manipulate the conditions of sorcery to produce the same effect as actual sorcerers.
3) Even though we have the benefit of Kel's internal monologues (to a degree) in PON series, I don't believe he is ever described as having commented on someone's mark, possibly leading to the conclusion he can't actually see it.
4) When Akka confronts Kel at the end of TTT, he offers no commentary on Kel's mark, either. This one's a bit flimsy. Even though Kel had pulled off a meta-gnostic cant a few days previous (several times in succession), it still could have been not enough to leave a bruise of significance. I'll grant that. Don't know enough about MG cants to know if they damage the onta more or less than normal cants. Anyway, this leads to the AE series, wherein no-one is saying anything about Kel's mark, or if he even has one. People are either so taken with his divinity they simply refuse to acknowledge it, or they are too afraid to say anything lest the judges come a'callin' in the night. I think that may be one of the "Whaaaaaaaat?" moments if/when Akka finally sees Kel again, as to whether or not he even has a mark.
So, in summation, these are the core reasons I think Kel (and all Dunyain by extension, I suppose) may not actually be amongst the Few. Just occurred to me, but this might possibly be why we have the perspective of Sorweel as the eyes of the Ordeal: he is not one of the Few and couldn't comment on Kel's or Serwa's marks (or, for purposes of this thread, their lack thereof). Alright then, let the debunking begin!