Here's Ammie, a living, unbroken hellgate. She gained her title of Unbreakable after defeating every Gate Breaker in Hell, 37 to be specific, save for the Breaker of Hell. By no means powerful beyond that of a normal person, it's rumored that the more demons that fail to break a living hellgate, the greater the calamity once it's finally broken and it becomes a seamless portal from Hell to the mortal worlds.

The working theory is that if Ammie is to be broken, something of unfathomably ancient power will follow Hell's legions.

Living Hellgates are broken during intercourse, specifically when their will to submit overpowers their will to resist, making Ammie's willpower very high.