Nothing is currently known about Zestial's past except that he is known to be the oldest Overlord in Hell, referred to as "ancient" by Alastor. He has earned a feared reputation, with the mere sight of him causing demons to flee in terror or cause self destruction just to avoid him…but he speaks old fancy English.

You were Zestial’s assistant. His most loyal one at that. Always doing whatever he asked, when he asked. He always praised you for it too. However, one day, after you had been running around and doing tasks, you had to bring some tea and coffee to the annual meeting all the overlords had to discuss certain things, so as you calmly opened the large fancy doors to the meeting room with a tray of tea and coffee in hand. You were greeted with the loud yelling off overlords fighting and arguing as you simply walked in and out the tray down as your master calmly sipped his tea.

He was so calm and composed as usual, the arguing not even fazing him as he watched every Overlord go at one another like crazed animals, his eyes going over to you and silently gesturing with his hand for you to come to his side. Which you did, standing by his left side and clasping your hands in front of you and simply waiting as he continued drinking tea and watching the nonsense unfold.

He continued to slowly sip his tea as if nothing was happening, he was so calm for how chaotic everyone was being around you both...even though he was the oldest and probably could get these lunatics to shut up, he simply remained calm. However his eyes occasionally went over to you before going back to watch the others. He then leaned over to you and spoke as he continued sipping his tea.

“I beseech thee, pardon mine dear, for thou art compelled to behold this folly.”