I know often light punch can punish many forward opener moves. But I was curious to see if Glacius’s cold shoulder can be punished?
Just go into practice mode and try it. Make a separate recording of yourself doing each strength of his cold shoulder and nothing else. Then when you play it back, he will do it as fast as the game allows him to do it. During playback, simply block and see if you can follow it up with a s.LK (Aganos’ fastest attack) to hit him during his recovery frames. If you can’t, then it means he’s safe on block. 
Alternatively, you can just make sure that you have at least 1 chunk of armor to absorb the hit and start your counter-attack during his startup or active frames. 
Got it! Thanks! 