Vi - Kinda fast speech, more soprano/higher, but not shrill. A teeny bit hoarse as well, with a little bit of that "tomboy roughness" that's such a trope in TV for spunky teenage girls. Also, just to make that cocktail more confusing, she's got a fairly noticeable Abeilline ("French") accent, just somewhat diluted by distance and an intentional effort to adopt the Formix accent (Ant Kingdom). Cross Maelle (Clair Obscur) with Beast Boy or Rainbowdash's rougher sound.

Kabbu - I cannot decide what I like more for him, but I think he's a baritone. Think rich, deep baritone but with some of the sharper timbre a tenor can achieve when he needs it. Either way he's got an impressive vocal range. If you've listened to God Shattering Star, Takashi Baba's performance in that is the sort of robust timbre I'm thinking of. In normal speaking, see also Count Dooku from the Clone Wars, just... less evil XD Also he's got a very pronounced Koele accent (northern beetle language), and slips into said language from time to time as well. Vi is convinced that he curses in Koele (he doesn't, but shhh). (Also for reference Koele sounds like some bizarre mashup of Russian, Nordic, and Japanese accents, if you can envision that.)

Leif - Obi Wan, honestly. Just take Obi Wan (clone wars or star wars, take your pick) and give him Raven's (Teen Titans) level of deadpan, and combine their sass levels. Fairly mundane accent wise - he's got the standard Formix Bugnish accent.

Celia - Nicole Coenen ("Okie dokie" girl with the axes, if you've run across her). Picked up Fornix easily, but her home language was something of a sister language to Formisci, so she's got a slight accent that would, if leaned into, make her sound vaguely Shakespearean to the average ant in Bugaria.

Levi - Plo-Koon from Clone Wars. That's roughly his tone, maybe a little bit higher than that. Has a mild Shirnik accent (Southwestern Wild).

Zasp - A little hoarse and raspy, but somewhere in the vicinity of a baritone, though while talking he sounds more like a tenor. Doesn't quite sound like a chain-smoker, but definitely sounds like he's got a persistent rattle in there. Has a residual Vespal-variant accent (old wasp language, not from the Grasslands hive), but it's fading over time. With all the traveling he does alongside Mothiva, he's accruing a more blended accent, with a particular disposition towards the Bee Kingdom's Abeilline accent (partly because Mothiva has that one pretty strongly). So he sounds raspy and slightly French, but also slightly Greek+Norse. (Also, this man can in fact sing. I'd put him somewhere in Bobby Bass's sound, if without as much low range.)

Mothiva - Most musical pleasant voice you ever did hear. Almost uncannily so. Ethereal, beautiful, soothing... but can get really screechy if she so desires. For a voice reference, think Lauren Paley and Eurielle. She's got a noticeable Abeilline accent since she's around the Hive and Golden Settlement pretty often, but also has picked up a bit of Zasp's accent, plus Formix from being in the Ant Kingdom, and has some diluted Elirnan accent (Southeastern Common) from her parents. Also, fun thing - musically inclined folks often pick up accents easier, which is 100% at play here :3

Maki - I really haven't figured out how this guy sounds, but I think his voice is maybe a thin tenor? Not nasally or whiny, just not quite so full as some. Perhaps something akin to Aragorn in the LOTR movies. He also has a faint Shirnik accent - it's worn off a lot since he arrived.

Kina - Similar to Maki, she's got a somewhat thinner sound, probably soprano. The difference is that when she gets mad, she doesn't get as much screechy as she does belt-y. It's not great for her voice and her voice tends to crack when she gets like that. She'd probably be able to do a pretty good vocal fry, if she trained it <.< Also has the faint Shirnik accent.

Yin - Fluttershy, but not so much shy as just quiet. Smiley happy sweet voice, she's adorable, she sounds snuggly. Picks up the Formix accent pretty quickly, but there's hints of something like Takai (Leafbug) in there.

Gen - Think Starfire's voice from Teen Titans, kinda. Just a liiittle less bubbly and obv with a regular speech pattern. Formix accent, of course.

Eri - Similar to Gen, but toss a bit of Raven's chill alto in there. Also has the Formix accent.

Stratos - Pretty laconic. Think Geoff Castellucci in vocal pitch with a full tone and a Scottish accent (Outskirts Formix sounds pretty Scottish). There's some residual Koele in there, and he is fluent, but the accent is pretty faint by now.