How old is your friend? Is he an innocent person, or as in, is he considered to be pure at heart? What month and what day was your friend born on? Well, there are a number of reasons why a demon, a particular demon, or spirit, will follow or try to possess your friend, if that is the case.
What makes a spirit able to possess a person, is if there is enough energy to make a 'jump,' or if that spirit is able to break your friends will. I should know about willpower, because I generally deal with that very concept almost everyday. What I mean by 'jump' is if a person emits enough given energy, at one time, that person can have a spirit take control of him or her.
Ever heard of a "witch's trap"? A witch's trap is a rigged cursed working, design to scare an unlucky person who happens to set off the trap. It is usually designed to get whoever stumbles upon one of these witch's traps. The general aim is either to put an immense curse upon that individual, and with the right curse and the expelled energy omitted, will be enough for demonic possession, if that is the aim. That is one prime example of why energy is important for a demon, in order for it possess a person.
Demons just don't come into a person's life for no reason. I've seen the common little minion demon, with my third eye, and have a sister to attest to a similar description. Little minion demons are commonplace. Those come and go.
I actually have much to tell you, and one more question. When this spirit does it's thing, is it always in the same place, or in the same home? Because if that is the case, then it is something within the home, generally, that belongs to that particular spirit, or it is an objext acting as a gateway for that particular spirit, which belongs to that spirit in a sense. The reason why I ask if your friend is pure at heart, and if the case is that this spirit is always manifesting itself in only the same location, this most likely means this spirit is a demon that wants to possess your possibly pure hearted innocent friend. Demons, if they are assigned, like to mess with someone that is pure.
It helps to know how this spirit got to your friend, in the first place. In other words, did he or you guys play with anything that you can think of? Excuse the term, play with.
I would just like to know if your friend has any special gifts. If that is the case, maybe he just needs to ground himself.
It seems as the pure hearted end up in these demonic influences. It could be through his parent's blood, because if the parents committed anything appallingly bad, that then creates like a spiritual door. It is like how young traditional heathens or gifted psychics claim they have their gifts because their parents were this or that. The same goes for bad things, as well as good things being spiritually passed down, through generation. For instance, I am labeled with my pagan name, and that name is seen by creatures in the spirit world, and it is because of my actions, that I have my particular pagan name. The truth is, we basically inherit everything through our parents. I don't think that is the case, because if you manage to successfully banish this spirit then another would just jump right in. In this particular case, it is not necessarily the spirit, it is a spiritual door way that is the problem.
Surely, what we do in life, echoes for an eternity.
I don't know if your friend is pagan, or believes in the occult, but if he has any path then he at least has something, potentially, backing his side. That would be considered a plus. I would utilize what faith I have, if I were him.
The only other thing I can think of, is if he touched something that he isn't worthy of touching, or if he cast a spectacular spell, but didn't please the spirits. It is like, you have these multi-gods and you work with them, and if you don't pay your respects in ritual work, you can get yourself into trouble.
What caught my eye, was that you mentioned two things. You mentioned that the spirit said something about a significant date. Well, by what was mentioned, symbolically, there is a time and a place. You just don't know the place exactly. The second thing was that you said your ritual didn't exactly work. Well, in this case, this very banishing ritual that you were trying was, in fact, working. By definition, that would be called an exorcism. I would say your 'banishing' ritual is working, but that spirit just doesn't want to let go. It is a good thing that you know its name, because that is going to be crucial in successfully banishing it. For a heads up, when and if this spirit manifests itself, in some sort of way, for who and or what it is, that is an omen, telling its end is near.
Well, yeah, you're going to experience some turbulence. Oh my good, yes, oh my good (German accent), I wish I was there to watch the whole thing go down. In the likely event of a nearly successful banishing, it may bring some of its friends along for the ride, and no pun intended. Ride, is a term used when someone lets one of their deities possess them.
Well, the Blood Moon, as this spirit is referring to, is significant. 'Normal' people think that and celebrate Halloween on the 31st of October, when in fact, Samhain is a three day long bonfire festival. Samhain starts on the 29th and ends on the 31st of October. Samhain, is indeed the harvesting Sabbat. Harvest is as to also offer up something, to appease the spirits on those nights, because not all the walking dead are going to be benevolent. Blood moon, and I will give you one hint. What was done in the past, but is now considered a taboo today? One word: sacrifice.
Maybe the spirit is trying to tell your friend something of mere warning. If it were me, on the three nights of Samhain, I would carve a pumpkin and light a candle inside of it and place that pumpkin right outside my house doorway. You place a carved pumpkin, with a candle lit inside of it, on these three nights of Samhain, to ward off the malicious spirits of the dead. Surely something is going to happen on the 29th. Well, anyway, one should always light a candle and incense on the nights of every new moon and full moon, between the hours of 10 to 1 o'clock at night, in my opinion.
I don't know if it is clear that this spirit is actually inside your friend, or if it is at the stage where it is trying to break your friend's will. I would ask to see what the spirit wants.