Mass unit explosion kind of thing

You know the Blood Mage's skill in ToB that has blood exploding all around him? I think its his ultimate... not sure

But i was wondering how do you create that effect?
I'm guessing its using triggers to create Blood Elementals around him then exploding them, and looping for a few times..

I tried that but it could only create a few elementals and explode them before it started lagging really bad

How do you do it??

If i tell you then you'll know basically how they did 7 of there hero's Ultimates, because 7 of there heros use the same Ultimate as a base spell. Im sure you can figure it out thought. It doesnt Involve triggers.

I have attached a map that uses the correct trigger. Just edit the values to what suites you best.

Um that looks nothing like ToB's Spell.....

I know, but with a small amount of tinkering it will do.

Um, its really not hard, just base it off stampede with a smaller area.