I'm not really use to doing 1x1 roleplays however I've done plenty of fate/stay roleplays, and have played Umbral Star/Grand Order. I haven't read the original visual novel personally however I have a basic understand of how it went for the most part. I tend only pair up with myself in terms of characters so while I'm willing to join up I'd much prefer to have a servant (usually), and master of my own making. My own character will probably be a re-used one unless you have an issue with him for one reason, or another (he's a fairly a-typical elemental mage). If you're looking for something else in this regard I understand but I'd figure I would throw that out there.