I AM attached to my characters in a way, but like a lot of things, I realize that they have to move on with their fictional lives. When their story ends, it ends. I've got a whole world out there, and like it or not, despite how I tend to make a big deal out of my current storyline, it's only a slice of the universe. I've got seven hundred years to work with, and at best, the story's only gone through five of those seven hundred years.
My current character for example has grown up during the course of the stories. He's getting married, has an ancient evil to stop, and the whole shebang, but I realize that there will be a time where I have to kill him off. As much as I like this character that I've used in some sense my whole life, his story must come to an end, and another one must begin, because that's life. It has to end sometime. Maybe there'll be more stories with maybe his kids, or maybe a distant descendant, but it won't be him forever.
Although, I have made a point to pretty much drive him to the point of insanity in the latest book, which may, or may not leave him with permanent mental scarring! Fun fun!
As for other characters, oh man, I just can't stop killing them! Depends on how important they are to the plot I guess. Ships blow up here, nukes go off there and nevermind the countless ground battles. So, it all depends on plot dependence for me.
I was overly attatched when I had but one character who I roleplayed with, inserted into fandoms, drew a lot and basically was obsessed over. About the only thing she didn't have was an actual life in an actual story because when I tried I realised how badly she fitted in a story despite being so so awesome in my head.
She is still beloved by me but never have I tried to write her into stories or such again for she is a remnant of my teenage days.
My current cast are 'beloved' and but not the same way. They exist to drive story and yes each one is dear to me in a way, but also there to be manipulated and draw a story out of my script. They're beloved for their purpose.
Bloody hell! My favorite original characters are the ones I put through the most hell! I killed off two of them before the first book starts (two faves out of twelve dead at that point) and another dies in the third chapter! And my main character is a freakin' eunuch!...
I played a Eunuch in a game of Dungeons and Dragons, once. You present being a eunuch as some kind of torment or terrible burden. Being a Eunuch was a rewarding profession for centuries in all kinds of cultures.
While that's true, I think most writers would view castration as a profound debasement of their character. Castration is something far out of the comfort zone of most writers, even those who otherwise torment their characters liberally.
Eunuchs did get placed into many powerful positions in the Persian, Roman, and Byzantium Empires, that's true. I've done quite a bit of research into the topic.
However, in my story universe, my MC is castrated as part of the sacrifice ritual that nearly ends his life and does kill his friends. It's not so much being a eunuch that's the problem as the memories the castration invokes. He'll get over it soon enough... and I plan to use his eunuch state as a means of breaking a few women's/girl's hearts and embarrassing some guys in later books, which will be a hell of a lot of fun for me to write!