This advanced, complete and free tutorial course goes through and creates a framework to give you a good foundation to build a complex and advanced RPG on top on.
Each episode is compact in time but full of information, teaching you different important aspects along the way.
Subjects, systems and functionality that is handled during the course: Levelling, stats (like hit points, mana etc), combat, status effects(buffs and debuffs), AI, abilities, damage, classes, animations, UI and much much more!
Part 4 handles creating a tag listener.
https://dev.epicgames.com/community/learning/tutorials/1GGR/unreal-engine-create-a-rpg-part-4-tag-listener