How to create an inline detector for if you killed a player with a certain tag

For example I want a function that runs every kill you get and checks if the person you killed has a "Jinx" tag. If so it then removes max health from you.
I am aware this is possible with advancements I am just looking for a less clunky system since I will have a lot of abilities that affect your killer in some way
Im guessing this would require predicates but not sure how