Ikr? Elves are usually portrayed as aloof and apathetic but Gil is such a good boy.
Also agree the death game seems very dissonant to the hero's behavior. He was neglectful and seeme to not care about his kids, but that means he also didn't give a shit about his legacy. All we see from him shows he was a very acarefree guy. It's his familiar that creeps me out. What the fuck is that thing? I feel like that is going to be important later.

Honestly Gil is such a good brother, and it's sad knowing that he's been a lonely wanderer for most of his life because of his parents. It's also surprising how he's able to easily sympathize and help those around him despite his initial appearance as a cocky playboy.
Also the siblings better start figuring out what the deal is with the death game because at this point it seems like something greater is going on. My running theory is that someone actually wants to get rid of the hero's kids. It would explain why losing the letter kills them, the true mastermind wants the kids to kill each other - whether directly or by destroying the letter. And money/inheritance is a good motivation.