When stories re-write themselves

So I WAS going to write Hex's first relationship into it's own story, but now it seems like it's gonna be included in the second half of Moon Eyed. So this story is going to be double the length of the first one. lolwhoops
That feel when your characters wind up writing themselves more than you're writing them. At the very least, Hex is a character I've had for like... 3? 4 years now? I don't even remember at this point. It's been at least 3 for sure. I could have sworn I posted when I first had him somewhere, but everything seems to have disappeared on me.

How long have all of you had your OCs and which is your favorite?

Edit: AHA! I found the first time I posted Hex on Deviantart. I guess the problem was that I had too many accounts over the years.
But here he is. Posted March 3rd 2017. So I guess my estimate of 3 years was the closest, since it's been nearly 2 and a half years.
Also what I find hilarious about Hex's design is that 1 year and 2 months later, the episode The Parent Map came out. Firelight's design still kills me to this day.

Here we have Hex:

And here we have Firelight:

Something tells me I need to write a one-shot of these two sleeping together just for the hell of it.