Ack, I just realized how "insanely edgy" Felix sounds from being said to be "a person who has suffered from depression their entire life", so let me explain that part a bit better:
Felix was born with twice the amount of testosterone as a normal male. Due to the high testosterone levels, Felix became more prone to having depression, which is what he ended up having at a fairly young age. Also because of these high testosterone levels, he has irritation issues, meaning its easier for him to get irritated/agitated/angy, as well have mood swings. Another result of this is him having a higher sex drive than most males, as one of testosterone's main roles is to give males a sex drive, so higher testosterone means a higher sex drive, I think. Now, if you were to research this yourself, there'd by lots of telling that it can also cause balding, higher chances of heart attacks, liver disease, acne, etc. etc. (trust me, I did my research, as I like to make my books as accurate as I can), but, hey, it's my story and my character, so I'm just choosing a few side effects to go with this thing he has instead of them all. With the depression and high testosterone thing, my main source is shown in the picture attached to this comment (I also added the definition of 'Androgens' since I assume most people don't know what it is off the top of their heads).
