They look fine.
Personally I don't like it that you are not allowed to parry the Eviscerator but not for balancing concerns (its fine) but for the fact that you can still parry a Bloodthirster's axe or something similarly large. I suppose its still better than giving them a parry even with frenzy like Khorne Berserkers.
I understand your point. I just simply took the original rules from Necromunda, even the wording of the description. It is more a weapon quality than the mere brute of the weapon's wielder that denies you a parry, much like the Mace of Valaan of Kyrinov.
You might want to clarify, if the 6+ save works also against all psychic powers (like I would say it does with the wording) or only against those with a strength value like fields do. I would say its quite thematic and should work against all powers without nullifiying them.
That was my intention. I changed the wording, so it becomes even more clear.