An Advance Reader Copy spell book — Donut's reclaimed floor prize — teaching a class-nullifying spell that won't activate until the twelfth floor.
The Tome of Gatekeeper is the spell book Princess Donut finally reclaims on the eleventh floor as the prize she was cheated of when the party skipped the seventh. Uniquely a paperback rather than a proper tome, its cover shows an angry human woman before a gate; the AI marks it 'an Advance Reader Copy. Street date: 12th floor,' meaning Donut can install the Gatekeeper spell now but cannot cast it until the twelfth floor.
The AI's rambling entry riffs at length on real-world fandom 'gatekeeping' before explaining the effect: for 75 mana it strips a target — opponent, NPC, deity, or mysterious 'OI entity' — of all class-associated skills and abilities for a short, intelligence-scaled duration, though a god will keep raw elemental powers (a lava god can still burn you). Neither Carl nor Mordecai can decode what an 'OI unit' is.
A slim paperback book — not a traditional spell tome — its cover a drawing of an angry human woman standing before a gate.
Donut's reclaimed floor prize, teaching the class-nullifying Gatekeeper spell for use on the twelfth floor.