Or you can create specialization trees that you could invest soul points (wich are gained with the succubus and or other characters, probably if so you should limit the succubus to an amount of soulpoints it can offer by saying that you have reach an certain treshold in wich her power could not increase your any more an dyou would have to search for an higher lvl npc to gain more soul points to invest in your specialization tree [that could be verified by counting the amount of points you already have gained]) into that can lead to the mc to being an more melee oriented (demonic/dark knight) or spell oriented character (warlock) in wich you gain specific spells if you follow that tree down or also you could be an acolyte (kinda mix between and spellcaster and mellee). The type you are currently is determined from how much you have invested into one tree or an other or both, if the game would verify that you have more points invested into the magic tree you would become an warlock else you would become an demonic/dark knight or if it finds that you have an close to even points invested between both trees you would be refered as an acolyte. Yet that way would have to change at the beginning of the game the mentioning that you are an sorcerer to something else. Also both trees could contain different power and magic increase upgrades (instead of doing that directly at the succubus) as you get deeper into the trees your total power, energy and magic would differ from the other tree, ex.: An only/full invest Spellcaster tree would end up having magic as it highest stat investment followed by power and as last energy and an only/full invested Melee tree would have power as it's highest invested stat followed by energy and as last magic.