Waepons with "Vicious" enhancement on it

[Pehtis]

Quick question regarding these weapons. In the description it says it causes a 'disruption' effect causing damage to both player but even more damage to enemy.

My question relates to the 'Disruption Effect'. I believe I read somewhere (I think Wiki on Necro2 quest guide) that Disruption Weapons insta kill Undead if they fail a save when hit.

Is that true?
Are 'Vicious' weapons 'Disruption' weapons?

Please advise.

[Lleren]

Viscious weapons simply do damage to both the player and the monster, regardless of any Damage Resistance.

They do not insta-kill Undead that faill a save, they are not Disruptors. The descriptive text may be unfortunate.