It's kind of a long shot, so don't get your hopes up too high. The first step is to write down everything you want to say to your brother. A letter isn't as good as saying it in person, but it's better than not saying it at all if you can't reach him.
[he steps back and starts pacing around as he talks]
After that, there are three things I can think of. Blossom has been able to send people home sporadically thanks to the first ritual. But I don't know if anyone has tried sending objects. I don't know if anyone has asked about it either. But...we could talk to Blossom to see if she could send the letter home. Since Nyx just left there might still be some link to your world, like a path that hasn't fully closed yet. There's no guarantee that it would reach him directly even if we got it that far. It's just a chance, unless Blossom has a way to make sure it ends up in his hands.
The second option is similar to the first, but we'd ask Red. He's able to get things from home. So for the right price he might be able to send things home too.
The last option is to find out if anyone here is from your world—anywhere in the world would be fine. And make a copy of the letter to give to each person. You'd have to trust them, obviously, and I don't know if that's something you would be comfortable with. But if they end up going home too at some point, then they could give him your letter.
no subject
[he steps back and starts pacing around as he talks]
After that, there are three things I can think of. Blossom has been able to send people home sporadically thanks to the first ritual. But I don't know if anyone has tried sending objects. I don't know if anyone has asked about it either. But...we could talk to Blossom to see if she could send the letter home. Since Nyx just left there might still be some link to your world, like a path that hasn't fully closed yet. There's no guarantee that it would reach him directly even if we got it that far. It's just a chance, unless Blossom has a way to make sure it ends up in his hands.
The second option is similar to the first, but we'd ask Red. He's able to get things from home. So for the right price he might be able to send things home too.
The last option is to find out if anyone here is from your world—anywhere in the world would be fine. And make a copy of the letter to give to each person. You'd have to trust them, obviously, and I don't know if that's something you would be comfortable with. But if they end up going home too at some point, then they could give him your letter.