Octavel was not an only child, being the eldest of three siblings, often presenting himself haughty and high. He found out his fathers origins in Ishgard and presented himself as such. However in combination, he was a holy terror of pride and defending those at the end of unfounded hate.
Currently, Octavel is a mellowed out gentleman. His heart shattered at the loss of his lover. He is nearly the spitting image of the victorian era man just remove the nasty bits. He is closed off just a touch, fearful that his heart will break just the same as that day in The Vault. On top, he no longer holds pride for ishgard, choosing to hold pride over his caring and firm nature.
I think that his extensive use of summoning magics with the catalyst he had chosen has caused nerve damage, making him have muscular problems at times. Short of it, He's got chronic pain in his fingers, arms, and hands as a whole.