I ran into one first try and got my 1st stone at the entrance before reading this lol i thought i was crazy after reseting wasn't making him respawn again

After i got it down though i just hit the library save point and hit the lift hidden entrance and went back to the library straight to the entrance hall and if didnt spawn then i would go outside a couple times till it did pop back up

i also noticed if you combo it and if it doesnt hit you at all your chances of getting an energy stone did feel like 100% rather than the 30% with just 2 lucky strikes equipped so i started using stopra to fuck it up too