Can I give you a few suggestions for the game?
Myrddin can, somehow, finally see the player. (without a sprite, for full immersion.)
The player chooses their description: including gender, hair color, eye color, etc.
Tell Myrddin jokes like: 'Is your head always in the clouds?' Or, 'Where am I? - on cloud nine!' Or 'It's a bit cloudy, today!'
Maybe, you can click on his hair, and ruffle it, messing it up. Or tap his shoulder to get his attention. Or hold his hand.
I was going to recommend showing a pair of hands, or just one hand, to represent the players hands, but only if you think it would fit in the game.
What about the player giving Myrddin gifts like a small ball, or a picture, or a keychain. Something to make his room a bit less empty.
Could the player give him food, too? Or, can he even eat without a mouth?
Anyway, these are just some ideas that wouldn't leave my head. I understand if you can't use all of them, I just thought they might be a nice addition to the game.