Teaching overseas one learns that the American idea of not having a relationship with students is not universal. Going into this school, we teachers were told to take time with students, and it has enriched the teaching experience. American teachers often say they don't have to be friends with students, which is true, but a colleague describes the relationship as "mentor-mentee."
I am reluctant to prescribe what the teacher must do/be as every teacher has strengths and weaknesses, due to genetics and upbringing. Some teachers can have relationships of this type, and some may not. I'm not saying what teachers must do, but what they may be able to accomplish.
This student has been bullied. Normally, when you see information about bullying for teachers, it's how to stop it or how to help the students to stop it, which is good. My classroom rules don't allow students to run others or themselves down--often it's phrased that way (when possible) to show that this rule is there to protect them as well. But is there something else we can do?
Why not be a mentor to this student if possible? Look at how his eyes light up about video games. Surely, he has teachers that share such enthusiasm. Why not have a friendship with a teacher who asks him about videogames--favorites, the new ones coming out, the best game systems, etc.? He may not have friends his own age, but maybe that's just a phase. What's wrong with having a grown-up friend-mentor? I recall a teacher speaking of a student, saying, "His only friends are teachers." So what? At least he has friends. It may not require hours of investment, but a quick minute to connect. Inventory student interests. Find out what they like.
Perhaps you cannot connect with the student--for whatever reason--but you might still be able to help indirectly. I had a student who wasn't bullied, but he was largely ignored by classmates. I handed over responsibilities to him so that others had to seek him for aid. Slowly, he gained respect and was even honored in a way that may have been a highlight of his high school days. He had many pulling for him, so it was the work of many people, including himself.
How might one implement this on student who appears to have no talent? You can hand knowledge to that student first and him to distribute it among his classmates. Going to someone for help implies respect for that person's experience or knowledge. Moreover, you the teacher imply that this student is worthy of trust.
It won't work for everyone, but it may be worth a try. This try may weigh far more than any bullying intervention you attempt.