If MegaGlest (or you, since you're using a custom engine, right?) were to implement GAE's effects, you could very easily have "life steal" and "mana burn" (assuming the former just absorbs health and gives it to the attacker while the latter simply damages EP).
How would I use effects to produce lifesteal and manaburn? I don't recall seeing that on the wiki.
Oh, I see it now, recourse effects right?
But is that really lifesteal? How would it get the precise amount of damage done to the enemy to apply the lifesteal % to? How would it deal with upgrades to lifesteal?
Yes, recourse effects along with a
<recourse-ends-with-target/> flag, so not 100% precise.