Overview:
The modification changes the basic Ciri sword on the more powerful or OP.

First version of my mod
5% Instant kill chance (without boss)

Second version of my mod
25% Instant kill chance (without boss)

Third version of my mod
100% Instant kill chance (only normal monster 1 hit, without boss)

Fourth version of my mod
100% Instant kill chance + ignoring the resistance to instant kill (1 hit all)

Installation:
Download with NMM and simply activate mod.
or
Download manually and unpack "modBetterZireael " folder to Witcher 3 main directory/mods folder. (example D:\The Witcher 3 Wild Hunt\Mods)

NOTE:
I used 
xml.bundle from The Witcher 3 Wild Hunt\content\content0\bundles,
damageManagerProcessor.ws from The Witcher 3 Wild Hunt\content\content0\scripts\game\gameplay\damage
Might be a conflict when other mod uses def_item_weapons.xml or damageManagerProcessor.ws
If conflicts try:  Script Merger by AnotherSymbiote 
If you have any problems, please let me know.

Compatibility:
I recommend my other mod Instant Kill Runestones <If conflicts try:  Script Merger by AnotherSymbiote>