Add effect to a Spell

[MN Lahmar]

Hello guys, i'm modifying the spell Bash to make it Give a percent chance to avoid attacks and to deal additional damage (without stunning the enemy even for 0.01 second). The problem is when the hero deals additional damage it's not noticeable to the player so i wanna make a special effect every time the hero deals additional damage.
Download the map down below and you'll understand.