I am playing a Divination wizard at the moment and quite disappointed that there are only 17 Divination spells, so I thought I would look at some homebrew ones to talk to the DM about.
The question is, that assuming I create balanced spells, what are the effects on the power of the Divination sub-class of increasing the total number of Divination spells?
In particular Divination wizards have:
Beginning at 6th level, casting Divination spells comes so easily to you that it expends only a fraction of your spellcasting efforts. When you cast a Divination spell of 2nd level or higher using a spell slot, you regain one expended spell slot. The slot you regain must be of a level lower than the spell you cast, and can't be of higher level than 5th.
I know that generally this isn't a well thought of power, but I am worried that, particularly if I add combat spells that this can quickly become overpowered.
A good answer will have experience of adding additional homebrew Divination spells into the game, but a well thought out answer which can explain the reasoning (or show some maths) will be equally well received.
For full disclosure, the party that I am with has a War Wizard, Wild Magic Sorcerer, Cleric (Not sure the sub-class) and Rogue. The spells that I am looking at would be combat related, probably one of each level from 4-8, with an additional non-combat spell from 6-8. None of the combat spells would do damage, they would all be defensive or offensive buffs (See this spell as an example, assuming the damage was removed).