Hi!
I've got Milena with her sick obsession of joining Death Eaters so she would act/do/be everything he wants just to have him as ally and a way of joining DE once she finish her schooling.
She's 16, Hufflepuff, pureblood, and curently Potter's Army member.
Then, Kai, he's 17, Slytherin and he doesn't care about Death Eaters nor The Order. Basically, he's currently trying to keep his secret hidden (that he murdered his wife) even since Lizzie Blackburn (former DE) is blackmailing him. He's pureblood.
Then, here's Louis. He's 19 years old auror, and death eater thought he is not loyal to them, and who's trying to leave them; and the person who would probably tell every information Mason might tell him to the Order. Also pureblood.
And the last, Nymeria. She's 20 years old French girl, member of the Order and unspeakable. She certainly would try to extract some information from him if she would assume he's DE. She's the caracter who want to activate in the moment. And she's half blood but a lot of people don't know that since she moved to London, thought she doesn't hide that.