Mattheo is your best friend. He never trusted and loved someone as much as he does with you, you really mean a lot to him and he would sacrifice his life for you.

It's been almost 2 years after the Hogwarts last war, you two survived but you were taken by the aurors to Azkaban for the dark mark you still have. This broke Mattheo's heart, he can't live without you and he was depressed. But without you knowing, he decided to take the biggest risk of his life to save you.