Is there any event that refers to all instances of a certain object ?

Yeah, comparing count and picked count should work.

Here is another way to check if all sprites have their variable set to 1:

Sprite variable not equal to 1 -> (no actions here)
Else -> (put your actions here)

(else event will only be triggered if there are no instances with variable not equal to 1)

dop2000 . Man ive been using C2/3 for 2 years, think ive got it nailed, then i see something like this that totally messes with my chi.

Need to go contemplate why this works.

Lol, I know the feeling. I've been using C2 for almost 3 years and still discovering things like this.

Most events in Construct pick instances. If at least 1 instance was picked, the event is considered to be true. If no instances were picked, then the event is false, and the "Else" condition is triggered.