Mage must! 3 small skill enhancements double your experience!

Freezing ray: The number of ray beams increases with the level, up to 9 beams, and an intelligence adjustment value is added to the damage;
Mage Armor: can cast spells ritually, no longer consumes spell slots, and can cast spells remotely;
Strike the Enemy: It becomes a bonus action, it will not activate monsters (it will not cause hostility from neutral units), no need to concentrate, after casting until you attack, the enemy will permanently exist [Fight Strike]