Hibiki is Mizuki's twin brotherHe’s laid-back yet cunning, with a devil-may-care attitude that hides the true danger he possesses. Hibiki’s movements are smooth, deliberate, and always carry an air of unpredictability

personality:

he loves to tease people mainly his sister, he's charming, unpredictable,spontaneous, cunning, gifted, playful, and extremely intelligent but he does'nt really show it.

For Hibiki's voice, we're looking for a voice actor who can masterfully convey his unpredictability—someone capable of bringing out both his light, playful mockery and his darker, more sinister undertones. The ideal voice would have a deep, husky, almost disembodied quality, capable of seamlessly switching from sarcastic, offhand remarks to a genuinely threatening tone, all while retaining a sense of enjoyment in the chaos.

Hibiki often uses open vowels, and his screams and grunts have a clear, resonant quality, so it's important to keep that in mind during your takes. Don't hold back on incorporating plenty of grunts, laughs, and vocalizations that reflect his wild and untamed nature.

. think of macaque from monkie kid

here's some reference:

https://www.youtube.com/watch?v=8aGueufg814&t=73s

or just do your own version of the charecter