This is one of the best lists I've seen. So great job.
Adjustments I'd make:
Unbreakable tier 3 [It's a decent character, but so are quite a lot of tier 3; too many risks that are full combo punishable.]
Metallic tier 3 [Tremor without IA quakes or armor just isn't in the same league, its good but not tier 2]
Warrior tier 3 [This character is not trash at all. No character with a safe special that can safe armor after is trash.]
Sorceror tier 2 [He's super strong no doubt, but he isn't tier 1. Mainly due to his defense on knockdown.]
Demolition tier 1/2 [Shes super good, like the rest of tier 2. It's hard to judge a character when only Scar represents her at the highest level and everyone else falls short even before the nerfs; she has a one dimensional play style and can struggle without exceptional reload timings and spacing. For me tier 2.]
Lasher tier 2 [Jumping around spamming whips is fun until a character has the tools to stop it and then hes quite bland, A tier 1 character doesn't care too much about the opponents tools.]
Hellfire tier 1 [One of the few characters that can slow the pace of the game down, can't be zoned, wins in the air for full combo. Excellent cancel pressure and throw game, with a super solid d4 and a counterpoke check (aura) you're playing his game.]
Ethereal Tier 1 [Same as hellfire, controls the game. Its her mistakes that will make her lose and the opponents needs to take risks to open her up, which are usually in her favour, don't jump!]
Stunt double tier 3 [I hate what NRS did to cage but SD is ok. He has a dirty counterpoke game with clones up and fullscreen mid projectiles and armored wake-ups are good.]
Konjurer Tier 4 [If the facehugger didn't whiff on low profiles or jumps, this would be a decent character, no
character can be competitively viable when its tools don't work due to hitbox issues, randomness puts this character in the trash.]
Tigrar Fury (possible tier 2) [Great frame data, solid projectiles, good character.]
Cyrax Tier 2 [With tri-borgs toolset {backdash,111,F13,throw,run speed,anti-airs} and the threat of EX-SAW in the neutral he can cause some serious damage to the opponent. Devastating set-ups and THE best corner game in the current meta; you best have that breaker ready.]
Smoke Tier 1 [As with all tier 1 characters, you play his game. On knockdown you have to respect his wake-up game and he has a nice little vortex. Add in his teleport cancel in the air (which can launch) and the cheap mix with a smoke screen. Hobart is the king of mix.]
Ronin Tier 1/2 [Great projectile - Excellent mid pressure - Safe air dash - Cancels - Decent mix. His wake-up game is what puts him out of tier 1 but that debatable, I'm on the fence.]
Hat trick tier 2 [Low pokes into specials, are cancer and this character embraces it with a passion. Ex hat-toss is underrated and the pressure he can create using it to stay plus is a strong mind game that the opponent has to respect. Great wake-up game and some decent set-ups.]
Lasher has more than just "Oh look i'm jumping all over the place!" he has everything that makes Takeda a solid character, he has good damage, some characters can not handle DF1 like AT ALL and it is special cancelable into a full combo. You HAVE to respect the space that this character controls which is damn near the whole screen. There is literally no character in the whole game that has normals that can control the space that Lasher does. You talk about having to play the character's game, that's exactly what Lasher does to you, he forces you to play his near full screen footsies game that most of the cast can't answer.
Hellfire WOULD be in Tier 1 if his lack of good defense was made up for in a significant way. He's got the setplay yea but in some matchups, his armor being the way it is makes for some TERRIBLE times. He is on the very cusp of Tier 1 (he's pretty much the best character in Tier 2)
Ethereal could be Tier 1, i'll have to look at that.
Konjurer is NOT trash tier. Holy crap. Okay, ignore the SOMETIMES having whiffing issues on facehugger (they aren't extremely common and are only common in the places they should be, jumping and low profiling.) he has solid space control, some quite disgusting setplay and just really good buttons that Alien has. There is absolutely no way in hell that this character is Tier 4.
Smoke suffers from a lot of people just not playing the matchup right. They let B2 walk all over them from fullscreen when there's plenty of people that can answer it. Smoke bomb on block isn't blown up nearly as much as it should be. Don't get me wrong, Smoke is dumb and super good but I don't think he's QUITE among the best in the game.
Cyrax having good setplay but only okay neutral (yes it's only okay, it's not complete trash but we can't ignore the problems with it, I should know, Leatherface has the same problems but worse) makes him struggle in a good amount of matchups (Mileena, Smoke, Liu Kang) All in all, the character has potential and I am 100% behind the "cyrax isn't trash" train but Tier 2 is a bit optimistic.
Low Pokes into special, while cancerous as hell, isn't going to bring Hat Trick to Tier 2. At the end of the day, it's a gimmick on block. His oki is pretty good but in the neutral he doesn't have a ton of meterless tools to help him out like Tempest and Buzzsaw have. In the corner he certainly becomes scary after a knockdown but we can't ignore his problems.
Metallic has Tremor's solid tools and loops you back into needing to eat those tools with restand. That's most certainly on par with Flex and IA Quake imo. Also huge damage, like, unbelievably huge damage, for no meter.
Unbreakable doesn't have that many risks. Literally he has two. B2 and Slide. Everything else is safe, plus, or neutral on block. He can slow down the game and make people think twice on oki. He also has the only one bar armored launcher which means he has the best armored move in the game (that isn't an over-exaggeration, there's a reason NRS took them out of the game)
Warrior has dirt, but the only problem with Warrior (and it's a fucking big one) is that his dependence upon meter is possibly the most out of any character in this game. He is absolutely USELESS without meter and that wouldn't be so bad if he had an actually good way to build that meter. He's never close enough to actually get anything off of his plus frames. The only thing he has going for him in the neutral is good armor. Which is fine for the most part but that armor no longer launches, which is a huge deal considering he actually just lived and died off of counter poking with EX Flip and trying to get you in the loop off of that. I can take another look at him but he honestly just doesn't get to play MKX for more than half the match.
FINALLY! Sorcerer. Now I know I said bad defense was holding back Hellfire but here's the thing. Sorcerer has way more to make up for that than Hellfire does. Sorcerer forces you to not have breaker throughout the entire match. If he lands one hit on you, meterlessly he gets a free purple rune and just strips you of your meter entirely. Secondly, armor rune IS THE SINGLE BEST MOVE IN THE GAME. Full screen, pretty much only one character in the game has a consistent answer to it (full auto) in the corner GOOD FUCKING LUCK. It's worse than Crystaline being in your face. Some characters have literally 0 answers to it in the corner other than just guess 10 times in a row. You can only guess right so many times. You say Cyrax has the best setplay in the game, Sorcerer is right next to that. Not only that but outside of knockdown situations, Quan's defense is actually pretty good. Backdash is godlike, pokes are really solid, his ONLY problem is on knockdown. That's his literal only problem. Everywhere else he is air tight.