By far the weakest character, and by far the most underwhelming, unless you're playing Impostor where he does slightly get a little better.
I see him as a good counterpick character with Impostor but by himself he sucks flat out.
General Issues: Has a 3,1,2 string that has a massive hitbox problem (all mids are whiffing after the initial low on a good chunk of the cast and it makes no sense, especially since his animation shows him elbowing you downward), 2,2 does nothing of use except combo filler in Impostor and that's specific. Only has 6 strings unless playing Bone Shaper and they're really underwhelming sans F2,2,4 which is great for whiff punishing. Hellsparks are decent against some characters but can be punished even if all three hit by a good chunk of characters. (I have been divekicked through them by Kung Jin and Lao, Raiden can superman through them even on block when I tested it out, and even when all three are blocked!) Not to mention he does just no damage. 1 bar midscreen is 28%. Even in the corner he does not do amazing damage, was able to get 35% (Not doable in Bone Shaper) throughout all variations without Mimicry combos. Sometimes EX Shoulder Tackle's fireball will whiff as if the second hit of it connects but not the first, the character will simply fall down. That does not happen every time however, which is an oddity.
Bone Shaper: may have a decent safe string in b3/f3,1,d2 but he still gets no damage compared to the rest of the cast, has great pokes but honestly War God Kotal is a way better version of this character minus the hellsparks, which aren't even that great to begin with. Also, in Bone Shaper his projectile is -12 ON HIT. F2, 2, 1+3 is really finicky too, mainly that if your opponent is mid air, the second 2 will sometimes whiff, and the grab portion will almost never connect for the most part.
Necromancer: is just lol worthy. Flick is the biggest gimmick, and he has no mixup so why even use the bar on the EX version to be on advantage (+3) unless you want the damage to kill? Maybe for a throw in the corner but eh. Not to mention you can just wakeup run through it so then you have to use the hellsparks so your opponent doesn't feel like he can get in on you for free, but he can. Unblockable hand is straight up trash. Even on a HKD it will not hit your opponent if they see that 29 frames of beautiful, glowy purple hand startup (EX is 39! All for a whopping 3% more of damage
) because they can backdash it, run past it etc... It does not track well at all. if they even stay on the ground on a HKD they will not get hit. Summoned Fiend is only used for EX combo filler in the corner, because it's just easier to confirm off of hellsparks and it does no considerable damage.
Every character, IMO has something in this game that makes them worth playing, but aside from pokes and the ability to whiff punish for little damage, you could be playing essentially any character and do better. Impostor is the only variation IMO, that can be viable simply because of Mimicry's ability to give you some mixup between a throw, a NJP, b3 into hellsparks (a low) etc... and the ability to vortex them a bit by comboing back into mimicry.
Lastly, I do believe he needs tweaks, but not necessarily HUGE OMEGA buffs to make him top tier, I just want him to be viable in the other variations. He's just not viable for me personally as I do not play Impostor and feel Quan Chi is a better character if you're looking for resets, so I moved on. I know Kit players hate not having mixup, well... You guys at least make up for it in raw damage and better zoning. I know it isn't much, but it's not Shinnok. (Also not saying she doesn't need tweaks either, that's from a pure observational standpoint.)
TL;DR: He needs a lot of help. Doesn't help he was made last either (thanks for
@RM Jonnitti for talking to two testers at Paradise Found and letting me know) and was initially designed to have Hellsparks be neutral on block, but was nerfed down later. So, I think he will get buffed eventually, hopefully at least the variations that are not Impostor get a bit beefier. Just again, do NOT give this character too much... Impostor I think is generally okay, if only because the air teleport and Mimicry give him escape options and reset options. Still has supremely unsafe strings, and the one that is -6 on block has no reach in 1,1.
EDIT: I diced up things so it read as sections as to what I think is meh about the character and not random blobs and blurbs.