I'm writing a birthday card and got stuck figuring out how to sign it. I want to sign as "Older brother Misha", but I'm not sure if it should be ミシャ兄さん or ミシャ兄さんより. I'm also not sure if writing ミシャ兄さん is correct, but I want specifically sign by name and as an older brother (if doing it is not completely weird).
I think this is mainly a matter of taste. But in my opinion I don't think people would normally write ミシャ兄さん. If you are going to use 兄さん, I feel like it is better to use より instead of nothing. You can also just write your name without anything following it (ミシャ). The only difference is that it feels more casual.