Kunimitsu in Tekken 8 embodies everything a great rushdown should be- basically, a migraine to fight.
I like rushdown characters. They're like credit card bills and insurance premiums all at once- here to make your opponent's life miserable. Your job, as it is, is to simply seek out what most ruins your opponent's day, then give it to them and then some.
Kunimitsu in Tekken 8 is very much this. Given how strong offense already is in Tekken 8, you'd wonder how you make a rushdown character feel distinct. The answer, as it is, is have specialists. Characters that live for this in a way you could never dream of. You might be pretty good at kicking someone in the shins. But you will buckle in awe at the sight of someone who can masterfully shin kick someone after distracting them first. That's Kunimitsu.
Kunimitsu in Tekken 8 builds on her identity as a stance-based rushdown. From her command dash Setsunagake to her backturn and Katon stances, the idea is that fighting Kunimitsu means you need to learn her one way or another to figure out where the threats are.
Guessing With Kunimitsu

Look at it this way- a lot of Tekken characters are capable of forcing you to guess for your life. High? Low? Throw, mayhaps? Kunimitsu does these things in a very cool and flashy way, like with her myriad teleports. From here, it's not just how she's going to hit you, she can mess around with the timing of when as her teleports follow up her strings with either a horizontal attack or a diagonal one. Using her command dash, you can force some pretty nasty guesses in neutral- she can either hit you high or low, with the third, more diabolical option of "nothing at all" where she will then be free to throw you.
What makes Kunimitsu fun is the myriad of ways you can play a very heart-heavy playstyle. She's got an anti air projectile that can punish those who try to avoid the guessing game by jumping, and the fact her pressure can lead into her stances means that even when she's not forcing you to guess, you've got to deal with knowing she's going to route towards a guess anyways. Many of her most basic strings can lead to either her Katon or Backturn stance- so you need to be ready for the possibility you're going to be blocking a while.

From long sequences to even Heat-enabled follow-ups, Kunimitsu feels like she has an answer to everything- which also becomes her weakness. People tend to forget the inherent trade off of being a stance character: while you're in one stance, you're locked out of the options of the other. Setsunagake is ultimately both her highest-utility move and a crippling weakness, since she becomes committed to the dash if you don't press any buttons. Backturn and Katon are very much in the same situations, where you won't have other options without having to first commit to leaving the stance.
Thankfully, she lives in a land full of plus frames. With some skill you can even start chaining stances together: Get in with Setsunagake, catch your opponent's low poke with backturn pressure, before comboing off of Katon. It's hard, but theoretically doable if you can get into their head.
If you're looking for that kind of mental-stack-abusing character, Kunimitsu is definitely worth keeping an eye on. She's flashy and technical in a fun way, and releases in Tekken 8 on May 28th for owners of the Season 3 Pass.