to be honest, this doesn't look like it's that threatening. looking at it frame by frame, there seems to be a good few meters in between the swords, so the attack isn't all that dense. Zohakuten would only need to block or dodge a fraction of them. and correct me if I'm wrong but from what I'm seeing, using the sword seems to drain her, so going for a full AoE attack that covers a radius of what seems to be a dozen meters or so for one singular target would just be a waste of energy,
sure, but being further away would also mean Zohakuten will have a way easier time reacting to and blocking attacks, so at the end of the day it comes down to infinite regeneration + infinite stamina allowing Hantengu to thrive in the long game.
the AoE nuke wouldn't really do much. due to the inverse square law, as the energy of an explosion expands outwards in a spherical wave, its intensity drops dramatically. if you double the distance of the blast, the shockwave's pressure is reduced to 1/4th of its power, if you triple it, then it drops to 1/9th of its power. essentially, for AoE explosions like this, Zohakuten and Minitengu would only be taking in a fraction of that power, and considering Shunguang's AP is initially a 1/3rd of Zohakuten's durability, with the gap only getting bigger as Zohakuten draws more and more power, then the nuke would honestly be less effective then her normal slashing attacks (Minitengu's durability is also like 300 Kilotons or something around that)
(also i may be wrong but in the clip you sent earlier, Shunguang seems to pass out after using the nuke?)
as for the WCS-like spatial slashes, I actually agree that they could do the job. the only issue is that this would have to be an opening move, or something that Shunguang does very early on, because Minitengu's little wood cocoon would instantly go underground and tunnel dozens of meters away before resurfacing, and will continue to run away on land afterwards. Minitengu wouldn't just be chilling on Zohakuten's shoulder or something.
if she completely erases Zohakuten in one swing, but the main body is still around, then Minitengu could just respawn Zohakuten or the other clones right back, so at worst it'll just become an infinite loop and a stamina game.
but if it's something she saves as a last resort or something that she does pretty late into her fights, then it becomes a question of how much power Zohakuten has drained. because as i mentioned before, Zohakuten continuously makes himself stronger and faster as the fight progresses, to the point of reaching a one-shot level above his AP and matching a speedblitz gap with his reaction speed. i'm not saying Zohakuten would blitz and one-tap, but if the spatial attack isn't a high enough amp in attack speed and is a late-game move, then Zohakuten will probably just have grown fast enough to avoid it. of course, i'm referring to the wide slash, because the thinner slashes (if they're also spatial attacks) would be regeneratable.
maybe? does telling "real people" from fake mean that she sees souls? because Zohakuten is made up of four major fragments of Hantengu's mind. they're technically the same person, but considering Hantengu can't actually control Zohakuten and they have a vastly different personality, I'd say it works more like separating a part of his soul and making it independent, in which case she would probably be seeing two completely separate entities, unless she can also see something like a spiritual link between them and understand that Zohakuten is empowering himself with Minitengu.
if it's just seeing past illusions and stuff like that, then i don't think it would really help.
it's possible, but if she uses her summit perception ability so see the that there are two separate living beings, i think she would just understand it as "strong big buy protects weak little guy".
also, Zohakuten's opening dialogue would be shaming her for picking on the weak (Minitengu)
i mean, Minitengu's durability is currently like 300 Kilotons or something like that, and his overall speed and agility are far greater than Zohakuten's, so to be honest I don't think Minitengu is gonna have much issue avoiding her AoE swords.
and Mintengu himself isn't helpless. of course, Zohakuten would be there to intercept anything flying his way, and if Zohakuten is gone then all the power that he drains would go right back to the main body, in which case it would instead just completely empower Urami instead.
to summarize my thoughts, I think Zohakuten's regeneration is too good and too fast to take any real damage, and his power draining would make him way too tanky and way too fast for any attack to matter in the long game. as long as he keeps an eye on Minitengu and applies pressure when he can, then he pretty much stonewalls everything thrown at him. i also don't think it's a stretch to say that Shunguang gets dismantled in an actual close fight, considering Zohakuten has multiple dense AoE, paralyzing and one-shot abilities on top of a nearly 3x AP advantage.
Hantengu FRA