Yeah but he wants it every level - thats why the bug is happening, it just keeps leveling and leveling.
It would be easy if it was every 10, because it wouldn't infinite loop.
I've got a fix for it.
-Trigger - turn off (this trigger)
-Set hero level of (last created unit....)
-Trigger - Turn on (this trigger)
Hoakey, but its the ONLY way around it I can see. 'Set hero level' qualifies as 'Unit - A hero gains a level'.
Isn't that stupid? Heh.