Whoever you were talking to has a weird nitpick problem.
I'm a lore snob across all of my games/universes and I think yours is just fine. She's supposed to be a Raen, yes? Then you're fine. I did do a quick google out of curiosity and found that the name seems to be actually from a JRPG character, but meh. Raen have Japanese names and you're not actually trying to BE that JRPG character (I also have no idea if you were even aware that character exists), so I'd say don't worry about this person and block them if they're determined to keep giving you crap for it.
I'm a lore snob across all of my games/universes and I think yours is just fine. She's supposed to be a Raen, yes? Then you're fine. I did do a quick google out of curiosity and found that the name seems to be actually from a JRPG character, but meh. Raen have Japanese names and you're not actually trying to BE that JRPG character (I also have no idea if you were even aware that character exists), so I'd say don't worry about this person and block them if they're determined to keep giving you crap for it.