I had come across this problem when I decided to ditch going for the strongest weapon and start using a weapon that my class can benefit from. Being a Privateer, I went with a staffy/slashy weapon. With the Pharaoh's Blade having something to aid dodging, I saw this fairly good since I don't usually get my player involved in the fight till i'm one of the few left. I had gone and fought the enemies in the skull island sewers were we meet Beemish. I threw myself in the fight and the sloth came and attacked me. He missed but Counterspell never activated. I don't know if its a bug or because its a STAFFY/slashy that I would have to have a magic user like Old Scratch miss me. If this is a bug, hoping for you to fix it soon .
Re: Counterspell on the Pharaoh's Blade isn't working
Counterspell only activates when a magic user either misses or fizzles, just like how Return Fire only activates when another Gunner miss. Although since it's a melee weapon, you'll need to be up in their face for it to work.
I use this weapon for fun as well, and using Vicious Charge on a Witchdoctor really made it effective.