Move unit toward target

This trigger is supposed to move the Mountain King past the Storm Bolt target, like a samurai running through a victim, but for some reason(s) it keeps moving him to the center of the map. Can anyone tell me what's wrong?

Here's the trigger:

Events
Unit - Mountain King 0016 <gen> Finishes casting an ability

Conditions
(Ability being cast) equal to Storm Bolt

Actions
Unit - Move (Triggering unit) instantly to ((Target point of ability being cast) offset by 100.00 towards (Facing of (Triggering unit)) degrees)

You should use

Unit - Mountain King 0016 <gen> Starts effect of an ability.

The finishes casting ability i beleive will only register casting unit and ability. This is because ability is finishing so will not need a target point to register.