Go kys or go to hell

I feel like the “go kys” line should have been more of a “go to hell” line.. go kys is an overreaction where as go to hell is another way to say fck off or fck you its an expression said in anger but can be easily rectified with an apology or in this instance an appropriate expression of anger that in my opinion wouldn’t have needed an apology, but go kys? Too harsh an expression to be thrown in like that even tho these characters are quick to their tempers… how interestingly thought provoking