WitchMaker
    A steel sword that was created by a witch that had a very strong interest in blades, is now regarded as one of the most powerful blades in the right hands.
    WitchMaker is a unique sword with a unique property that not only increased magical effectiveness, but also melee effectiveness.

Where to Get it

Currently you can buy it from the Grandmaster Smith in the blood and wine expansion. you can also acquire it by this command when using the debug console.

additem("WitchMaker")
And the silver version for sabres is
additem("WitchMakerSilver")
and for silver version sword it is
additem("WitchBreaker")

The Effects
    As you use WitchMaker you gain charges that increase Sign Intensity by 5%. There is no cap to how many charges you can have, but the more charges you have, the quicker they dissapate.
    
    The maximum charges that will apply to sign intensity is 40.
    
    Each sign cast consumes 1 charge for every 10 charges you have rounded down. Only up to 4 charges.
    
    Each sign you cast while using WitchMaker adds an effect to the sword. These effects last 40 seconds each. This is not refreshed by casting a different sign, but is refreshed if you recast the same sign.
        Yrden - Adds a slowing effect to the sword.
        Quen - Adds Armor peircing
        Igni - Adds chance to ignite
        Axii - Change to stun
        Aard - Chance to staggar
        
    For each sign on the sword at the same time melee damage is increased damage by 10%

    If you have all 5 signs on the sword at the same time, WitchMaker goes into sign overload causing 100% damage increase and increased effectiveness of individual sign effects for 20 seconds.
    
    Effects I may add later
        A yrden autocasts on sign overload initiation
        A Arrd 360 autocast on sign overload initiation
        A Igni 360 autocast on sign overload initiation
        A Quen autocast on sign overload initiation
        And no one likes axii