But Zoro didn't even fight Kaku in Egghead they just clashed briefly, so I don't quite grasp what you're trying to say. Isn't this kinda countering your own argument lol?For Killingham, he manifests dreams into reality, so I don't see the correlation with Ashura, which is mainly a Haki thing (just like Kin'emon manifesting fire through his sheer will). I'd love if Zoro vs Killingham dug into the Grim Reaper scene from Onigashima then I'd def agree. But tying it to Ashura feels kinda far fetched..
Yeah, Zoro only clashed with Kaku (it would have been pointless for a full rematch anyway), but the irony I'm pointing out is that Zoro's frustration with fighting "wriggling" or dragon-like opponents is coming full circle in this arc, where he runs into the upgraded version of Kaku.
Again, "kirin" and "giraffe" use the same katakana (キリン), so the Kirin is the mythical counterpart of the giraffe. I also find it interesting that Killingham has a centaur form, which bears a resemblance to Zoro's future opponent, Nusjuro. This potential fight could be seen as a warm-up for that future one.
So, in summary, you have an arc antagonist who has the Mythical Zoan version of Kaku's fruit, has a centaur form, summons demons (think King of Hell), is a bladed-weapon user, and works alongside a Sanji-coded opponent (Sommers).