Just a hint here, the units doesnt have to be based on a far seer, the important with "Unit-Order Unit to Orc Farseer-Chain Lightning w/e unit" is that the spell your dummy has got to have (in the object editor):
Text - Order String - Use/Turn On: chainlightning
This is the Order you call to activate this spell. To activate it via trigger you use the "Unit-Order Unit to Orc Farseer-Chain Lightning w/e unit".
This means that you can have a shockwave based spell, and change the orderstring to "chainlightning".
Make sure the spells orderstring is set to chainlightning.
If this wanst the problem, im not sure what it is.