Firstly, you would need to get the intervals set up (could be a simple periodic event that you turn on/off) and then you would need the actual stealing of the life, which would look something like this:
Trigger:
Actions
Unit - Set life of (Casting unit) to (life of (Casting unit) + (Max life of (target unit of ability being cast) x 0.02)
Unit - Cause (Casting unit) to damage (Target unit of ability being cast), dealing (0.02 x (Max life of (Target unit of ability being cast))) damage of attack type Spells and damage type Normal
Excuse my freehand. You would need to run that at every interval until the spell is over. I'll leave you to figure the rest out. As for the visual effects, I've never been very good with lightning effects...
I'd say, use a dummy unit which casts life steal for the lightning effect and move it periodically to the casters position. keep in mind, the GUI action to move a unit instantly will interrupt channeling spells, however you can set a units X and Y directly with jass which will allow the dummy to keep casting the ability.
i would also use a damage detection system in combination with the dummy caster. whenever a unit is damaged and the damage source is the dummy caster make the target lose 2% of the casters (not the dummys) max hp and make the caster gain 2% of his max hp. obviously the drain mana ability of the dummy shouldnt deal any damage then.
I am working on getting access to the old news portal under a different URL for those that would rather use that for news before we get a different news view.
It is OK though for the main page to open up on the forum in the view it was before. As long as the portal has its own URL so it can be viewed that way I do want to try it as a regular forum view for a while
I switched it to a "Standard" article forum. This will show the thread list like normal, but the threads themselves will have the first post set up above the rest of the "comments"