He is named muscaria thanks to wikipedia. thank u wikipedia, i lov u even if you want money from me

Lore wise, Muscaria is a minor sphinx deity whose powers rely on dimension stuff.
He is unaware of his worshipped deity status. It is like those old people that go outside with a "FUCK MY PUSSY TILL ITS ALL SORE" shirts without knowing what it means. Then somone photographs them, and they get famous, and they never really know about how popular that photo is much less they know what their shirt means. Or maybe they know. But well.
First he was created upon an interrupted ritual that was all about creating some sort of dimensional gap to hell using a crystal as a gateway. A certain blue thing got in, fucked things up, the crystal exploded into a lot of tinyfucks going to dimension buttfuck nowhere and muscaria was born. Getting with him a blue colour, dimensional powers, imortability and ways to use those crystal shards as a comunication device.
Those crystals are named shooting stars or wishes from their shape and the incredible fact that people use them as pseudo dragon balls. If you whisper a wish while holding a wish shard and break it in two, one of the parts will teleport to another dimension containing your wish as an encrypted message. Muscaria is attracted to those crystals so he will go after it, and eventually he will be able to listen to your message. He may grant your wish or not, it is all up to how much he is willing to do something at that day. Most likely he will pick the crystal and add it to his crystal hoard.
His dimensional powers are from jumping between dimensions to creating dimensions of his own - his home is a small private dimension where he leaves all the shit he gets. He often stores a very small and unstable dimension inside his collar, using it as a "bag dimension" where he will store all the things he gets in his travels in.
Muscaria is unable to die, but shooting him or injuring him too deeply will force him to turn into space dust and return home. In this proccess all the unstable dimensions he had will break, making him drop some valuable loot - loads of items from loads of dimensions, but mostly crystal shards. This makes him an often hunted deity, and people will try to entrap him or steal something from him in order to force him into granting wishes (like searching something for them or doing something. blelp)

On his personality; muscaria's attention span is minuscle. he is semi-sentient, becoming full sentient if triggered with social interaction. otherwise he will just be a dumb thing looking for shards, like if he was on autopilot. this is a self defense mechanism so he will not die of isolation. he lacks social interaction to have a deep personality, but he is pretty ????? !!!? ???? ?!??? at most stuff. Yeah that is a good personality description. I was tempted to put that watermark right above his boypussy