Spell Help Request

Spell Help Request

Can anyone help me about this spell.
I have a Character Assassin
This is her skill

1st -
(Active)
Dual Strike - Instantly teleports the assassin at the back of his target and create an illusion in front of her target that deals bonus damage.
Level 1 - Deals 40 bonus damage.
Level 2 - Deals 80 bonus damage.
Level 3 - Deals 120 bonus damage.
Level 4 - Deals 160 bonus damage.

2nd -
(Active)
Assassins Break - Randomly Teleport at the back of the Enemy Heroes in the map who has low life that deals bonus damage.
Level 1 - Randomly Teleport on enemy hero that life is equal to 350 and deals 250 bonus damage.
Level 2 - Randomly Teleport on enemy hero that life is equal to 550 and deals 350 bonus damage.
Level 3 - Randomly Teleport on enemy hero that life is equal to 750 and deals 450 bonus damage.

I dont know how to create a trigger in jass only GUI..
Can you make an illustration like
Event - (Etc.)
Condition - (Etc.)
Action - (Etc.)

thank you!!!

Assassins Break

Event-
Unit begins effect ability
Condition-
Ability = (ability)
Action-
Unitgroup units in playable map matching coditions -
unit is a hero
unit hp less than or = to (health)
add to (unitgroup)
Set (target) = random unit in (unitgroup)
unit move (triggering unit) to position of (target)
unit issue order (triggering unit) attack (Target)
unit (triggering unit) damage (target) (damage)

hope this helps