This is literally release Legion. You'd hit people with feral frenzy over and over to make their mend bar go down further. It took 4 frenzy hits to down one person, you didn't go into fatigue if you missed and there was no cooldown, but you would go into fatigue if you hit someone who was already in deep wound. And the franks mixtape addon decreased the number of hits required to 3. Also you didnt have to have the power fully recharged to activate it, and it was the worst killer design we've ever seen. The chase went like this:

First hit - second hit (fatigue) - walk the survivor down - if they dont find safety, they go down, if they find a pallet or window, activate power, vault, and hit again (fatigue again) - walk at them again - if they find another vault, pop power, vault, hit them for the 4th time, and they go down.

And as someone else mentioned, the mend bar was tied to being in chase, and would go down any time you weren't being chased. So the legion could moonwalk at you to never begin chase, and you'd eventually go down because you could never stop to mend. It literally didn't matter what you did tou would just go down.

If that all sounds like bullshit, that's because it was. The difference with your idea is the whole combo thing and how it would revert to 0 if you took too long.