My kid (15 M) has to face a whole group of bullies today at school, can he have some words of encouragement?

My kid had a mental health crisis during the sjmmer and these kids made his year last year hell. Today is the first day back at school and he's going to have to face them.

One girl lead him on then made fun of him and told everyone. It's gonna be a tough day.

Can you Redditors give him some words of encouragement? Thank you!