Demons start out with a lifespan of 10 minutes
Killing things adds 5 minutes multiplied by the killed targets normalized health to 0-800 capped at a max of 2, but never going beyond the 10 minutes
Soooo… what does that mean in English?
Say you kill something with the hp of 1000 in a range of 0-800 that would be 1.25 so that would be your multiplier (remember it’s capped at 2, so killing something beyond 1600 health will still just count as 2)
That 1.25 would be multiplied by the 300 seconds (5 minutes).
which would result in your final demon life extension of 375 seconds, however it’s hard-capped at 10 minutes all the time so any excess would be lost.
Your demon will also gain a level after every kill provided the target had at least 75 health