Thank you! the thing is though, i take the treat, show it to him without kneeling down (i don't have to call him, he always follows me everywhere) and once i go down and present it to him, within a split second and without even sniffing the treat, he lunges towards my hand, blindly taking whatever he manages to grab, and then tries to run off. I tried closing my hand before, but he just keeps biting my hand instead.

However, i have found a method that seems to work quite well, but is unethical because i basically force him to stay near. I go outside to the balcony, close the door, then put it on the ground while petting him. The first few times he tried to escape despite the balcony being only 1,30m x 1,40m and even jumped straight into its glass door once, but fast forwars to today, there's a 50/50 chance he'll be gentle and eat besides me, still growling however. but it's progress.

I should have mentioned that he was found in a cardboard box at 1 month old according to the shelter and hasn't got any socialization other than from my other cat, the tortie. I feel like he is still just too young and inexperienced and probably had to fight for his food on the streets and he still carries that trait.