combining two spell

[KHAN]

I want add bash to critical strike and also change the
percentage like this:
lvl1:5% chance 4x damage 0.5sec stun
lvl2:5% chance 8x damage 1sec stun
lvl3:5% chance 20x damage 2sec stun
I dont know how to create this spell.

 

[Rui]

The bash ability also has a Damage Multiplier spot. Delete the '25' on the Damage Bonus and fill in the Damage Multiplier instead.