How do I create periodic special effects?

[kewlthis]

Lets say I want psi storm explosion effect appear on my unit every 1 second for 10 seconds. How can I do this?

I could add periodic damage with behaviour + effect, but I cannot find how to add special effect with behaviour or triggers....

+rep for the wise man who solves this

 

[kewlthis]

Wow i actually managed to make it with behaviour, alltought it spams the effect and its not perfect, its acceptable...

GJ me, im amazed how I did that

*edit*
I mean behaviour + effect + actor....