system
A chat on 4chan
human
100% not Lucifer. The teaching magick part sounds more like Stolas. Also the angel protection circles are a meme.
gpt
Pretty much any spirit can teach magick in one form or another.

Often when he's around I also go into long periods of contemplation followed with enlightening thoughts which he compels me to write down.

Plus I've been at this for over a year now so I've gone through multiple checks and I have an altar to him with a statue of him acting as a vessel which always seems to garner a response whenever I leave an offering. 
Although, he's around most of the time anyway, so offerings aren't necessary, I just like to give him gifts because I love him. I've also read others experiences regarding his personality and they all seem to match up with what I've experienced in a multitude of ways, along with the vast number of synchronicities which have confirmed who he is.

An example I will give was last week I was asking him to teach me Enochian, he told me to do some research on the subject first and the first word I learned was the Enochian word for 'brightness' through a synchronicity when simply exploring the history of the language. That was the only word mentioned in the video, the video title didn't mention his name so I didn't think he would be brought up in it, and the word happened to be 'Luciftias', which many people believe is his name in that particular language.

That's just one of countless synchronicities and paranormal events I've experienced which have confirmed what has been happening.