I think you have to really pull things to very far extremes to prove that literal unconditional love doesn't exist, but even then it has problems. There have been mothers who loved their kids even after they became serial killers and stuff.
But not all of us are blind followers of LaVey. I see no reason that there can be unconditional love, which to me just means that you are not expecting anything in return. I can see though that, you can't unconditionally love just anyone or everyone, so what if that person changes? I'd argue they are not the same person anymore. So perhaps unconditional love doesn't last forever, but it at least exists.
I've never had kids, but I've had animals that I felt I loved unconditionally. In a way our brains see pets as like babies and so loosing one can be worse for some people than loosing an adult loved one, particularly since we have no culturally recognized rites of death for them. A lot of Satanists like to edgelord about hate, guilt and all that, but none ever talk about grief, which is in my opinion much more destructive than hate or guilt, and a stronger emotion that can persist for years and years after it doesn't ****ing matter.
Most hate stems from something active, ongoing. You don't see many people raging about someone they hate that is dead, and you can't feel guilty if you don't see it as bad anymore or don't do it anymore. But grief? That **** can stick with you for ages, and it's not always about a living being that died. It can be about an identity, something that once happened but you lost and won't ever experience again... it's about loss.
Love is about having, and grief is about loosing. Those are the two most powerful emotions I think. Not love and hate, which at times can be on a razor's edge of difference, but two that are utterly different.
Unrequited love is both love and grief, and is one of the most intense things, the most painful, amazing and irrational things someone can experience. We are nonsensical beings, and you will never convince someone with unrequited love that their love is meaningless. I don't see why it should be incompatible with Satanism anyways. Yes, in a relationship it's a two way street. But if your not in that kind of relationship, and it is what you want to do, what's wrong with that? Is it masochistic? In a way, yes. But life is filled with pain as well as pleasure, it's normal for any relationship to have some strain it's how you deal with the stress and bull****, it's how to deal with the "pain" aspect that defines who you are, how mature you and all that. But selfish? Hardly. Everyone has to deal with the good and bad in people, that's what being in a relationship is about. So unrequited love is maybe an extreme, but I don't see it fundamentally different other than it has grief instead of the insane stress that sometimes accompanies long-term romantic relationships.
