Myochin Kabuto BCNM, "A Thief in Norg?!", completed solo as Samurai/Dancer (re-quested the artifact to store the set).
Hagun, 300% TP (Meditate twice), wait on the recast, Sekkanoki, Yukikaze>Gekko the Summoner (did Aerial Blast, resisted for like 200~ damage), pretty much brings it to 10% or less, definately kills it if you double attack.
Meikyo Shisui, kill the Black Mage, which it will die within a full Y>G>K Light skillchain. Be sure to range Burst if he decides to cast it during Manafont and you don't actually kill him with the full skillchain.
Once you're down to only the Dark Knight, swap to Soboro', and you can toy around with him, like what I did for this screenshot. The fight's mainly about executing the other two before they drop your HP too low (incase of an unresisted Astral Flow or -ga II/III).
No +HP medications used, but mind you, I highly recommend going as /DNC for IF you do manage to take a sly bit of damage.