I started to see the whole picture :
覇気 = Haki
魔気 = Maki
鬼気 = Kiki
Kiki can be interpreted as a combination of Maki and Haki.
Kiki demonstrates a
domineering presence, which parallels Haki. Both Kaku and Kaido were shown
shivering when Asura was unleashed, emphasizing the overwhelming presence emanating from Zoro.
At the same time, Kiki displays characteristics associated with Maki:
additional arms and additional swords are manifested, mirroring the visual aspects of Asura.
So, rather than being purely Maki or purely Haki, Kiki can be viewed as a power that combines
Maki's manifested form with Haki's domineering presence.