TurinTurambar
Adventurer
Might I make a suggestion regarding Moon Magic?
Instead of increasing the DC of the caster's spells, allow them to cast those spells as if they were of a higher caster level. That, or allow the casters to count as a level higher (like they were in previous editions). While this doesn't allow them access to new spells when they are of a higher level, it will allow them to access to more spells and the ability to cast one of their known spells at a higher spell level.
Just a thought.
Nice thought, but I´m afraid that I don´t follow you. The caster level in 5e is a diminished factor in comparison to spell slot used to cast a spell. In most spells you have to spend a higher spell slot to enhace the spell efects, so enhace the effective caster level it won´t necessarily enhace the spell.