Hi! I got an idea for your Miraculous Guardian in Hell. And I found a website to help you with the Old English.
Here are some ideas that I thought Zestial would say when he first met Musa:
"My word. It couldn’t be. Could it? She't be mine wife. May she?" Zestial thought in shock, staring at Musa.
"Why, good day, mine dear~ What endues thou hither ? I've ne'r seen a human hither 'i this Hell, alive. And thou bare the resemblance of her." Zestial greeted, taking Musa's hand and kissing it.
As for a long conversation with Zestial's wife, that's gotta be hard.
Here is the link to help you: https://lingojam.com/ModernEnglishtoOldEnglish