Gaining Stats

How do you trigger it so (I dont even know if this needs triggers) but when your hero kills a unit your hero then gains 1 to each of his mains stats.

so...

1 Kill =
+1 to Intel
+1 to Strength
+1 to Agility

and it stacks.

Ok, depends on what circumstances you want it. Anyway, the main trigger would be something like:

Event - A unit dies
Conditions - (Killing unit) equal to Hero [or variable] -> This is the case where you ahve a specific hero
OR
- (Killing Unit) has Level of Ability (your ability) greater than 0 -> This is the case where you have an ability which does teh stuff
Actions - Modify Strength of (Killing Unit): Add 1
- Modify Agility of (Killing Unit): Add 1
- Modify Intelligence of (Killing Unit): Add 1

Hopefully that's what you seek.