In the Egghead Arc, Zoro briefly clashed with Kaku and said he was tired of fighting wriggling things because he had just done that in Wano, i.e., dragons (Kaido and King, the latter's Ancient Zoan DF being a Ryu Ryu model and having a neck-stretching attack, Tempuraudon).
Now here's the irony: in the Elbaph Arc, Killingham is essentially an upgraded version of Kaku, and I think Oda will match them up because of that.
In JP, "giraffe" & "kirin" are used interchangeably, as キリン refers to both. For example, Kaku was referred to as Kirin Ningen in the JP RAW and Giraffe Man in VIZ's translation. Killingham has the Mythical Zoan version of Kaku's fruit.
- Egghead, Elbaph
- Kaku, Killingham
- CPO, Holy Knight
- Giraffe, Kirin
Killingham may not be a swordsman (not that it matters, since he uses a weapon), but his DF ability is about manifesting (dream) demons, while Zoro can manifest Ashura through sheer willpower. This could potentially lead to an interesting interaction and perhaps an exploration of Ashura.
All are weapon users like Killingham

... except Lucci, but his epithet is "Massacre Weapon."