Shikanoin Heizou, the Analytical Harmony, illustrates the hypocrisy of USA media quite well. When Heizou was first revealed in May 2022, some people in the USA said he looked 'mid'. Then after Heizou's voice actors were revealed in the 2.8 livestream, do you see these 'mid' comments as much anymore? This shows that the USA media, FBI, and elites put a lot of undue weight on the character's voice actor when in reality the voice actor is often chosen to be the opposite match for the character. This is the case for characters like Tartaglia or Yun Jin. This may or may not be the case for Heizou, but that will ultimately depend on his in-game story.
As a catalyst user, Heizou has some pretty unique normal attacks, resembling martial arts kicks and punches, which is interesting for a detective. As of 4.2, Wrio is another boxer type melee catalyst.
Heizou's E is an example of an Anemo nuke and can reach even 1000% total scaling, which is quite high. He also has a cheap 40 energy cost burst.
His burst is another example of pseudo-quadratic scaling. It only has a limit of up to 4 enemies. If there are more than 4 enemies, it is no longer quadratic scaling. Ganyu, Ayato are other characters that have this 'fake' quadratic scaling. It is only quadratic up to a certain limit, after which it is no longer quadratic (but linear). Childe is the only character with real quadratic scaling.
His burst also has some cc (though not as much as Venti/Sucrose/Kazuha). His C2 buffs the vacuum field's pulling effects.
One of his passives gives 80 EM to other teammates after using his E. This is pretty good. By comparison Sucrose gives 20% of her own EM as EM to others. So if Sucrose has more than 400 EM, she can give more EM than Heizou.
Heizou's c6 buffs his own crit rate and crit damage. His c6 is almost like a troll to Xiao mains. Gorou's c6 buffs the crit dmg of geo characters, Sara's c6 buffs the crit dmg of electro characters, you would think that Heizou's c6 could buff anemo crit dmg for others, but nope, it only buffs his own damage. But that's why we have Faruzan folks.
One, it shows that Heizou is more focused on sub-dps than support. Two, it's not like pyro or hydro characters have crit dmg buffs either (at least as of version 2.8). As of 2.8, only electro, geo, cryo (via Gorou, Sara, Shenhe constellations) have crit dmg buffs.
One can use ttds for support, but since Heizou is more focused on damage and sub-dps, the widsith, tulaytullah, kagura verity are also good for crit stats. Desert Chronicle 4 piece is bis for damage. VV 4 piece can be used for support and damage.
As an Anemo unit that can use vv, Heizou can be used on any team that needs vv. Heizou does not provide as much support abilities as say Sucrose or Kazuha, but Heizou may provide more sub-dps. Heizou can be used on Xiao teams for sub-dps, though usually Sucrose would be more helpful as a battery.
As a main dps, Heizou relies more on normal attacks, so Yun Jin can help buff that. Moreover, Faruzan will be the best anemo buffer for his dps too. In general, Heizou can be played in similar teams as Scaramouche. The difference is that Scaramouche will tend to do more damage. Otherwise, it's usually recommended to run Heizou as sub-dps/support.
Heizou can work as a hyperbloom NA driver (e.g. Nahida-Raiden-Furina). His passive that buffs team EM can boost hyperbloom damage too.
Assume level 13 E, max 4 declension stacks each time, 61.6 anemo dmg bonus. The cd is 10s. Total scaling is \(483 + 120.87*4 + 241.74 = 1208.22\) so it classifies as a nuke (usually > 1000% scaling). The dps is $$x_E = (1208.22*1.616)/10 = 195.248352$$
Assume level 13 Q and that at least four opponents are affected by windmuster. The cd is 12s. Total scaling is \(668.71 + 4*45.59 = 851.07\). The dps is $$x_Q = (851.07*1.616)/12 = 114.61076$$ Total dps is $$x_E + x_Q = 309.859112$$