Cramming experience beyond the limits with Though Bottle

[Samael Morgenst]

Let's suppose we are in a world that don't allows for levelling beyond the 20th.

An ingenious wizard puts his memories and experience as a 20th character in a Thought Bottle, then uses a drop of Styx water to erase his xp, and restart his adventures training into some other class. Once he's satisfied, he recovers the Thought Bottle and

BAM!!!!

All the old memories and experiences are forcefully crammed back into his little brain.

Plausible result?

[Morphic tide]

Mechanically, Thought Bottle just sets XP to the point of storage -500. This means that XP past 20th level needs to be possible to store "Wizard 20", and it technically "shouldn't" do anything special because they're already at 20th level so they don't gain anything from the XP.

In terms of fuzzy-logic, this would be decent justification for converting the character to gestalt, and the procedure's understandable for applying AD&D dual-classing rules. But the rules actually written don't do anything interesting here, it's when you do stuff like stack Lycanthropies, store that ECL, cure them, then retrieve the XP.