Hey y'all, I need help. 

So, my best friend been diagnosed with bipolar a good while ago, after going through a major manic psychosis episode, after which he started to be very spiritual. 

And I mean, the whole 9 yards with talking to god's, Tarot cards, buying books over books over books about spirituality and telling me stories about how he gonna have to save the world to combine this realm with the realm of the gods. 

I try to be supportive as I can be, but I begin to reach my end and I just don't know what to do. 
Day after day, I listent to him talk about how god's scared away demons hunting him, listen to him talk about his past lives and everything he wants to do/has to do. 
Now, he told me, that he wants to learn Norwegian, Hindu AND mandarin, as this is the 10th time this year where he came up with languages be want to learn (and already spend well over 500$ on language apps) 
I told him, that's it's honestly impossible to learn 3 languages, that are so vastly different from eachother. 
Now he's massive pissed at me, tells me that I never supported him and never accepted his spirituality and that learning those languages is helping him connect with his past lives and he's doubting our friendship just because of that. 

I'm honestly at a loss, I just don't know what to do, this episode has become more intense and I'm worried that he will go "full psychosis mode" (quote from him) again. 
He talks about the evil spirits hunting him, shows me 'prove' of said spirits (like the number 13 on the cash register), is looking up ways to red rid of the curse a evil Egyptian god as placed on him and I could go on and on. 

Please help me, seriously I have no idea what to do or how to handle this, to make things even more difficult, we live on different continents.