I have created a legendary level system without NWNX for Arkhalia PW, but it was removed from the game later from game as other DMs thought it goes against our goals (aka players played one character instead of choosing different character for each dungeon - caused some problems in game with creating the party when nobody wanted to play certain role) anyway there are details:
- First legendary level(LL) starts at 5milion XP and each other is 5milion XP more
- Each class grants different bonuses on LL, example: wizard +1caster level +1dc +1will, fighter +1ab, +1dmg, +1discipline
- Player usually can select more than one class when levelling based on the level distribution - it works similarly to the multiclass xp penalty, prestige classes are always a choice to improve, base classes only the highest level or in case of match.
Thats all, no feats to choose, just automatical bonuses.
Notes:
- The caster level, DC modification depends on a spellscripts from my unofficial patch and won't work without it.
- Bonuses are applied as a supernatural effect which is reapplied in number of occasions like rest, respawn etc. These bonuses are intentionally visible in effect list. And the player is informed about his bonuses from LL each time they are reapplied.
- CAP is a factor to this system.
- Depends on a database, Ive done this using NWNX actually and MySQL but it can be modified to use native bio DB.
Thats how I made it and I can definitely share it if you like it. Everything can be adjusted but directly in a script - it is not toggleable by 2da or module variables.