ky0resu is vtuber adjacent singer who's been speculated about in pretty much every generation and wave since HoloEN Council as she's been fairly inactive the last year or so.
She's a memelord, has a fair-sized YT channel, and she speaks english/spanish/russian.
As far as I can tell from quickly looking at the archives the rrat on /vt/ is she sings and Fuyo has posted a lot about her (Fuyo speaks Portuguese and Spanish).
That's it.
If ky0resu got into a corpo I'd expect it to be Holo or Niji, she's an absolutely massive-sized catch for a small corpo, as in, bigger than any one small corpo combined. We will see I guess.