Bright, cheerful and childish, Gale is someone who smiles and does whatever he wants, when he wants. He starts and ends things on a whim, especially fights, but more often than not stays with what he has going until he gets it. He's very adaptable, especially when it comes to new situations and other people, settling in faster than a newborn child. However, underneath that smiling exterior is a child who has little morals and little empathy, like a child who doesn't quite understand why kicking puppies is bad. He has few attachments in life, allowing him the ability to become utterly ruthless to others, but what few attachments he has he holds with determination that rivals the world itself, even if they're toxic to himself. Occasionally, he can focus on things so much that he gets stuck and resistant to change, similar to the reverse Death tarot, but eventually he'll attempt to move on. Stationary in personality he might seem, and he realises that - which is why he's trying to change. Much like how the Death card represents transformation, Gale is trying to change his own personality and lifestyle for the sake of his loved ones, something he approaches with zeal - even if he's not entirely sure how to get about it.
The Hawthorne family is a high ranking family, one which has reach and is full of affluence, made up entirely of pureblood with disdain towards humans and diluted blood. They might be few in number, but all of them are extremely powerful, disciplined in all their ways. Brought up by the family, Gale had been forced to be mature and disciplined since day one, which might explain his exuberant and overly childish nature and tendency to say sound effects out loud. Constantly reminded that he was part of the great Hawthorne family and should therefore behave as such, Gale was smothered with rules and responsibilities better suited for an experienced adult than a child. For a while, he used to escape to play in the streets and release stress, but when his grandparents and relatives found out, he received hell for doing so and was monitored until he reached his eight birthday, where he drew the Death Tarot.
He had even greater responsibilities entrusted onto him after that, held apart from the others due to being one of the major arcana. Nothing he did had ever been good enough in the past, and it was the same now. Being in the school provided little relief - until Gale found himself a friend, an older boy called Ciro who treated him like a normal child instead of someone to be despised, feared or of great responsibility. It was a ray of light in the darkness Gale felt, and he held onto it like a drowning man gasping in air, and away from his family's influence, he grew away from parroting his family ideology into forming his own views -something that his family found terrible.
Gale's family was toxic, himself more so - which is why nobody stayed. but Ciro did, and that was enough for Gale to change his viewpoints on certain things. It would take time considering Gale's avoidance of responsibility, but Gale has the rest of his time at school to figure out whether to cut off ties with the family he holds in high value, or to cut off ties with Ciro like his family wanted and continue on their legacy.
Gale has the power of transmutation. With his runes, he has the ability to change one thing into another, by deconstructing that thing and reconstructing it into another object. For example, take a cement brick. Gale has the ability to deconstruct that brick into its base form and reconstructing it into a cement duck. This only works only on inanimate objects, however, and he can't transform it into something the thing isn't made of - for example, he can't transmute the cement brick into wood, as cement doesn't contain wood. He likes to accompany this ability's activation with sound effects, but its not a necessary requirement to activate his ability - although its constant use might convince people otherwise.