Micolash Fight Part 2?

I was going to get the Moon rune by doing the "make contact" gesture. On the way down, right outside of where you get the blood rock, an NPC (maybe Micolash? It had the same arm attack as Micolash and he was spraying some type of mist at me. He wasn't wearing the cage hat though) attacked me. This didn't happen in the tutorial video I watched. This guy seemed pretty strong and I died instantly

Was this Micolash? Why did this happen? Am I stuck fighting this guy if I want the moon rune now?

Thanks