>>96108384 (OP)Every magic class should have to be a sliding scale of power vs freedom to use it. The most powerful magic users should be reliant on patrons or gods or other forms of pact to give them magic beyond mortal means, and those all come with strings. A cleric has to follow the dogma of his god. A warlock is a slave to their patron. A demonologist is bound up in the complex legalese of his contracts, and so on.
On the other side of the spectrum you have wizards and sorcerers, who are more free in what they can do because they are not in debt to some extraplanar force, but the tradeoff there is that their magic is weaker. They might not have to bow and scrape to a god like a cleric does, but the cleric can manifest actual miracles and the wizard can't. Their power is entirely their own, but that means that there are tiers of spells that will forever be out of their reach.