In rummaging through my game stuff, I got to paging through a copy of the Magical School Lunar character design reference sheets I picked up on Yahoo Japan several years ago. Sets of these sheets were widely available in that market at the time. I don't know whether my copy was actually used by one of the staff, as reference sheets are sometimes commercially released. Unlike my nicely-bound Neo Angelique: Abyss character sheet book, though, the Magical School Lunar sheets consist of a bunch of relatively cheap mimeographs held together by a single staple in the corner. There were, though, rampant listings on YJ of a few other Lunar items of unknown provenance - possibly not commercial, but seemingly not bootleg; maybe from sort of convention - in the same time period: copies of the SSS ref sheets (less common than the MSL listings but still in significant numbers) and a set of an Akari Funato enamel pin of chibi Luna & Lucia and an example of Lunar currency (from Vane) that had one of the dragons on it. I never bit on the SSS sheets, as they seemed to contain the same drawings available in the commercial SSS books, but I regret not picking up one of those dang coin/pin sets. They were so ubiquitous at the time that I put off my purchase until, of course, it was too late.
Anyhow, the MSL sheets. One of the first pages concerns how the characters' eyes are colored: for most, the irises are a flat, uniform black. (I think this is a mistake: it makes the art look as cheap as, well, it is.) The exceptions are the magic-race villains, who are directed to have their characteristic red eyes. Though Barua is mentioned by her eventual name, the sheets reveal that apparently, until rather late in production, Memphis's name was going to be..."Delvis."
Admittedly, Lunar has generally gone the ヴィ route over the ビ route in representing "v" (see Vane/Vheen/ヴェーン), which suggests that it's more likely "Derbis," which comes with its own problems.