Lusaire's name was a name I originally made up for use in MMOs as a kid. When I was little I had a habit of making up random names for my characters instead of using real ones (although like anything else, I'm sure Lusaire exists as an actual word/name somewhere in the world). I've used it and various different iterations of it over the years. It just seemed fitting to use it for my fursona too, since I'm comfortable with it, it's pretty unique, and it's basically never taken on any game or social media platform I go on, which is a nice added bonus. It has a neat high fantasy feel to it as well, which fits with him being a unicorn/dragon hybrid.
Stephanie got her name when I asked a friend for suggestions and she was like "lmao steve from minecraft" and then uhhh the feminine version actually fit her super well
Iza got her name from https://www.fantasynamegenerators.com/
's portuguese section because her species is native to Brazil
Constantine gets his name from the three Scottish Kings named Constantine (Causantin Mac Cinaeda I [862-877], Causantin Mac Aeda II [900-943], Causantin Mac Cuilein Calvus III [995-997]), who i'd been researching at the time as a hobby. I wanted something authoritative to match his personality, yet regal in contrast to hint to his past.
Zalifa got theirs like Iza, from https://www.fantasynamegenerators.com/
's Malagasy section. However, I actually got a few and ran a series of polls. They could've also been named Claude, Emilie, Tsiraka or Simone.
Ozzie got his because uhhhhh his species is australian. also it's short for oswald, and he comes from a wealthy background but doesn't like to associate with it, hence he prefers the dimutive form.