Hey mate Iv seen your video and its awesome, at the moment I am trying to do a similar combat system based on animations as you have.
But currently mine does not work and I was wondering If i could have some help. 
my sword does not have its own blueprint, its an object in the character blueprint thats attached to a parent socket, and the collision of the sword is childed to the sword itself, both by default have no collision.
I can play out my sword swing animation just fine,
I also have set in the anim graph so if attacking is true set collision of the swords collision to the player channel and if attacking is false then set collision to none
Within character blueprint itself where sword is held iv set up a BeginOverlap and Hit Events but neither fire off when im practically swinging my sword in another characters face or against the wall
Would you mind talking me through this/what im doing wrong?