Set owner problem

Hi, I wanted to do some system, when mob dies - give reward to killer. But if mob dies on lava because of killer - @trigger is not a player and of course there is no reward. So I decided to set player owner of mob on attack end on death give reward to owner. But there is nothing

Here is my mob setting:
DZombie:
Type: ZOMBIE
Skills:
- setowner @Trigger ~onAttack
- skill{s=DZombieReward} @Owner ~onDeath

Skill DZombieReward works on @Trigger, but not on @Owner. What's wrong?
Using...

Set owner problem