Fuegoleon - The most intelligent captain now featuring the power of Salamander. Potential Wizard King candidate in my mind.
Mereoleona - Absolute powerhouse. Boasts an undefeated record on the battlefield and touted as a legitimate genius.
Yami - It's fucking Yami.
Nozel - Extremely balanced. Had a really bad matchup during the Reincarnation Arc so don't let that cloud your judgement of him.
Jack - Given enough time, he will cut through any defense.
William - Never really impressed me, but still the captain of the strongest squad. That counts for something. Maybe move him up one?
Rill - Extremely volatile power. Can go up or down depending on his inspiration.
Charlotte - She's portrayed as strong and competent but not super impressive outside of what Charla did to Yami. Her power is weakened due to her curse though so she could get even stronger if it's broken.
Dorothy - Powerful ability, but it can be manipulated by her captives somewhat. I think she's a witch so she may have some powerful hidden abilities related to witchcraft?
Kaiser - Praised as the "Kingdom's Ultimate Shield" but we need to see more offense.