Ah, well. Memory fails again! But yea, I'd at least argue that the Thanos instance showed/proved, he could kill him rather easily. Helps that he casually dismisses him in Infinity, by punching him out of a leap before leaving Proxima to deal with him.
Also.. Yea. Hulk did win, by, uh *sigh* slowly walking over while Gladiator stands there and stares at him real hard. Then, manages to grab him by the face, KO'ing him with his own attack...
I mean there's a LOT wrong in it that, but it does prove that killing the Hulk through his HF is a thing that can happen. Zeus breaking it for awhile is good definitely above your typical Class 100s but I wouldn't give it up as something special for a Skyfather.