Man, trying to list all the key players in 'Alpha's Broken Mate' is tricky because everyone argues about who really matters. The main two are obviously Alpha Logan, who starts off as this brutal, cold pack leader, and Ava, his 'broken' mate who gets rejected at the ceremony. That rejection scene lives rent-free in my head, honestly.
Beyond them, you've gotta include Marcus, Logan's Beta and the voice of reason who low-key has a thing for Ava? It's complicated. Then there's Selene, the scheming she-wolf who wants to be Luna and causes most of the drama in the first half. Honestly, I found her a bit one-dimensional until the later chapters where her backstory with her own pack comes out.
Oh, and Ava's human friend, Claire! She's not in it much but she's crucial for keeping Ava grounded outside the pack politics. The real dark horse character for me was the old healer, Alaric. He shows up maybe three times total but every piece of cryptic advice he drops ends up being a major plot point. The author was playing a long game with him.