[TBD] AKA the Professor
Alias: The Librarian, The Archivist, The Loremaster, The Researcher, The Headmaster, The Master of Novices, The Weakling, The Grand Advisor, The Hermit, The Annoyance, That Accursed Gnome, GAAAHHH!, The Simpleton, Griggory Flopwoodle, The Undying Mage, The Knower of Secrets, etc.
Race/Species: Forest Gnome (D&D 5e)
Age: Very, very old. Has lost count of just how old by now. Looks like he is just regular old.
Alignment: True Neutral
Class/Profession: For character class (D&D 5e): Bard/Cleric/Druid/Fighter/Rogue/Sorcerer/Warlock/Wizard, for occupation, see all of his names (his time as a GAAAHHH! was relatively short, but enjoyable, and he often does a little bit of it par-time between his other jobs) but in the Nexus it is mostly just the first 5.
Power Rating: Probably a B or B+
Description: 3' 7", pale skin, a few wrinkles, but not many, blue eyes, usually smiling, bald with a long white beard (he kind of looks like the default gnome wizard forum avatar).
Personality: Generally fairly good natured, but also often quite sarcastic. Rarely reacts to anything with surprise, awe, fear, or whatever, due to having seen almost everything there is to see. Dislikes combat, but if he feels threatened (which he rarely does) he will not hesitate to defend himself.
Equipment: Wears a grey Robe of the Archmagi, and holds a staff that is basically a Staff of the Magi and a Staff of Power glued together (both visually and in ability). He also carries a Deck of Many Things. The character concept has access to other magic items, but I will probably avoid using them in any meaningful way so as to avoid having a Deus ex Machina toolbelt-style issue.
Abilities: He basically knows almost every cantrip in the 5e PHB or Xanathar's Guide to Everything (all but 3, which I have not chosen yet), as well as almost every first level spells and a large number of the second level spells in both books. Additionally, he is okay in physical combat and stealth, and being a high-level D&D 5e gnome, is pretty durable (high HP) and somewhat resistant to magic. While he has no overt weaknesses, he is fairly unoptomised for combat, because while he can throw out a litany of different cantrips indefinitely, he knows know spells of third level or higher (other than those granted by his staff) and only has up to seventh level spell slots.
In the beginning, there was nothing. Then, the DM (his name was Ethan) spake thusly: OK guys, you can use anything from the PHB or Xanathar's, have your sheets done by Sunday for the first real session.
And lo, Sunday came, and [TBD]'s creator (his name was Josh) spake thusly: I have my character, but I can't think of a name, I put TBD on the sheet for now, but I'll fill it in by next week.
-From The Book of RNG: A True Telling of the Creation of Our World by Griggory Flopwoodle
People, careless people, create worlds and abandon them. One such group of careless people included Ethan and Josh, and when session one ended in a near TPK (only Josh's character, an as yet unnamed forest gnome, survived) they decided to just buy a campaign module and start over with new characters. But their world persisted, and so did TBD. Being a PC freed from his player, TBD had a greater understanding of his world than the would-be NPCs around him. If he focused, he could tell what CR something was, detect the space-time anomalies that occurred in six-second cycles during combat. He could even, when he meditated deeply on himself, understand the nature of his own stats, and with them the nature of spellcasting. What he realized was that the most powerful skill was one which could be done forever, and so was the most powerful spell: the cantrip. He also understood the nature of classes, multiclassing, and feats, and he used them to slowly level up to 20, eventually learning 36 cantrips, the maximum possible with any combination of multiclassing and feats short of a houserule (at least using "anything from the PHB or Xanathar's"), out of a total of 39 in existence (also under the same restraints, Ethan didn't allow SCAG spells, UA, etc.). He even got enough XP to gain the Epic Boon of Immortality (which stopped him from aging) after which he chose to stop leveling up or gaining abilities. In that time and the centuries (or was it millennia? It's hard to keep track) that followed, he traveled the Campaign Setting. He did it all and knew everyone. He worked at, founded, discredited, destroyed, rebuilt, and repurposed countless schools, kingdoms, religions, and even people. Eventually, he couldn't keep going. His long life and the loneliness of being the only person in existence to understand that people are all statblocks eventually took its toll on his resilient gnomish mind, and he began to go mad. And then, a portal appeared. Not a regular portal to one of the outer planes (all of which he had explored extensively, but a different one, one that felt... statless. He grabbed his staff and deck and jumped in. On the other side he found the nexus, and there he learned that he could see no stats (well, he could sometimes intuit the stats of other D&D 5e based Nexus members based on the appearance of their abilities and a subtle tickling feeling he got behind his left eyebrow, but that hardly counted). In the Nexus he built a new library and school for himself, and their he has stayed for a very long time.
Miscellaneous: He recently spent several centuries in suspended animation after an incident with a magical artifact.