Idea for a Resident Evil-style pursuer adversary

I've been running a little homebrew sci-fi adventure with my friends and it's been a lot of fun. The PCs are currently exploring a dark laboratory full of unethical experiments, and I've been meaning to inject a little bit of my fondness for RE into the gameplay next session so I came up with a complex little passive for one of those classic pursuer-type adversaries that Just Won't Die (Nemi, Mr. X, etc.).

This is just my first draft but I kinda like what I have going on here so I wanted to share in case someone else is running a spooky adventure for their party or wants to take some inspiration:

Pursuer - Health listed on the card counts as a single instance of Pursuit. You must spend a Fear to initiate Pursuit. The Pursuer is spotlighted when Pursuit is initiated. When the Pursuer's HP reaches 0, describe how the Pursuit ends. (e.g. An avalanche of loose rocks from one of the PCs' attacks undermines the platform at the right time, sending the Pursuer tumbling down into the depths below)

Initiate a countdown after the first Pursuit ends equal to the Pursuer's maximum Stress. Each time a PC fails with Fear, reduce the countdown by one. When the countdown concludes, you may initiate another Pursuit.

I'm thinking that I would do a separate card for such an adversary's actual boss fight and its different phases, of course. This is just something to help me keep track of chance encounters with the party. The HP on these Pursuer cards would also naturally be lower and the max Stress higher to keep a sense of tension between encounters with the enemy and not making each encounter too long.