If you go to Father, on Deimos, to browse his Orphix Venom wares and you click the Mods category, both the mods and arcanes are listed. Its not a big issue, but given the other vendors(little duck, Zuud, Hok, & Quill Onkko) have specific arcane categories, it seems strange that the arcanes are grouped with the mods.   FYI this was an issue in Scarlet Spear too.