SC2Mapster

You want your templar to spawn two copies of the target unit with a Spawn Unit effect, to do this you left the Spawn Unit field on the effect set to "none" and that was it.

But now you just get copies of your _caster_ unit with these same settings, and changing say "Type Fallback Unit" to anything other than caster creates an error that doesn't let the effect fire at all.

What do?

You need to adjust the following:
Effect: Type Fallback Unit + (None):Target

Also, it just shows "error", if you link an ability to the effect with that fallback unit. You need to put a dummy set between the ability and the create unit effect to make it work.

I've attached a map including the working ability.

edit:
I wrote a bug report about that in the British SC2 forums: here

Doh, and I knew about the Set trick too, thanks a lot.

Quote from Trieva: Go

I was wondering if the hallucinations copy the behaviours of the target units. If not how could it be done?

You can make them do that. Check my attachment.

I'm learning a lot while solving your tasks/problems. :D

Btw, if you enable "preserve", then the behaviors are reset with the duration (but I didn't check whose player's catalog entries are used for that).