Well, after a week or two of just gradually becoming lethargic despite treatments, Caspian passed away today. I'm pretty certain it was just old age. I've had him for almost two years now.
Caspian was my fifth betta fish ever; it was Fitz, Pierce, Flair, Demi, and then Caspian. I named him Caspian after the seafaring King from The Chronicles of Narnia. He was the biggest fish I'd had yet, and by far the loveliest, with his shiny turquoise scales. When I first had him, I took photos of him in this random temp bowl I had, and he was so excited to be in these things. His was the first bubble nest I ever had from a betta.
I'll miss you, little guy. Thanks for sticking around with me for so long. I'm glad I could give you a good home, and you could give me a best friend.