A second brain that
keeps your canon.
Most AI tools hand you generic fantasy and leave the bookkeeping to you. The Loremaster is seated inside your campaign: it answers from your world's live state, writes real records into your codex, and leaves an audit trail you can revert line by line.
It answers from your world, not the multiverse.
Ask about the storm-singer you invented three sessions ago and the Loremaster knows him: his faction, his secret, the location he haunts. Its context is your campaign's live state: the world primer, the entity web, session recaps, and a rolling memory of what you two have already decided. The same page you see here is the page it reads.
Ask for a rival, and a rival exists.
“Give me a rival for Ulva, someone from the Free Captains.” The Loremaster proposes a full record, with description, personality, stats, loot and faction ties, and on your approval writes it into the Cast, linked to the people and places it references. No copying out of a chat window. It was never a chat window; it's a co-author with a pen in your book.
It preps the night with you.
The Session Sheet keeps the Loremaster in the left margin while you shape tonight's secrets, quests, and beats. Ask it to draft a strong start, surface the threads you left dangling, or stock the treasure hoard. Everything it suggests lands as cards you can stage, edit, or discard.
The full writ of powers.
NPCs, locations, quests, factions, pantheons and deities; monsters, spells, items, feats, backgrounds and subclasses; traps, treasure, mounts, familiars, encounters, handouts, random tables and notes. The Loremaster drafts them all, into the same editors you use by hand.
Plan mode is a pure sounding board: it can read your world but cannot touch it. Flip to Build when you want the ideas written down. Over-generation is impossible by construction.
Pin the entities tonight's session turns on and the Loremaster holds them in mind across the whole conversation, plus everything they're linked to.
Every tool call is logged. The writes you would want back, meaning new records, edited fields and whole imports, store what they replaced and revert in one click, from the chat itself or the AI Activity log. Generated art is the exception: it is not taken back from the log, it keeps its own version history.
Ask for a portrait mid-conversation and the image lands on the entity's record with a full history, and regenerating never destroys the art you liked. Meet the Illuminator →
Point Claude, ChatGPT or Gemini at your campaign on any paid plan and it reads your world and writes records back, with the same audit trail and Undo as the Loremaster. Your agent supplies the intelligence, so reading and writing your world spends no Isometra AI credits.
Players chat with Lyra the Sage, grounded in their character sheet and the rules, walled off from DM secrets by design. She helps them play sharper, not peek further.