[@Sedjwick] The stat needed for spellcasting is tied to a specific class. Clerics and Druids use wisdom for their Divine magic, Warlocks, Sorcerers and Bards use Charisma as they don't really know how they make magic, they just do. Wizards and Artificers use Intelligence because they have to study magic. Skills like Arcana are more your Knowledge of the subject, not your skill in using it. For a battle mage type character, there's archetypes for those in Wizard and Warlock. Bards can also do this fairly well.