thank you once more for your quick answer!
i actually got mine to work right now, seems like i just misschanged something. it looks like this:
system for "check" from 1 to 4
-> [array], Value at (loopindex, 2) = 0
-c> object instance variable = loopindex -> destroy
-c> this is an additional condition and the -> a sub-event. then i threw in some more conditions for everything i want to destroy with the instance variable, which has a 0 in the array at It's X.