In order...
1. Behold! Two Welfare five-stars and a four-star! This is totally normal, right?
2. Matthew is True Neutral, with some decidedly amoral leanings. Very few things keep him in check, but he is easily influenced by those around him once they manage to endear themselves. Ritsuka is a good influence so far, and having Kadoc and eventually Hinako and Pepe will help. Also I needed to get that bit of backstory out to establish why he would be as brutal as he will be during event 1. Matthew is not a bad person, exactly, but he is not a good person. He is a creature of utter whim that is placid when undisturbed, and willing to unleash a total war when agitated.
What he did to Marisbilly was A Bad Thing, and he shouldn't have done so. Caspan is actually in the right, though it doesn't account for any personal changes he might have undergone in the four years since (this takes place in 2019-2020).