Combat Caster

 Ability score increase: +1 to  Intelligence, Wisdom, or Charisma

Reactive Support: When an ally you can see starts of ends their turn within 5 feet of you, you can use your reaction to cast a spell on them. The spell must have a casting time of 1 action, and target only that creature.

Preemptive Magic: When you roll initiative, you can use your reaction to cast a spell. The spell must have a casting time of 1 action, and the spell must target only you or an ally.