I would say Muu, Yamato, Kinkaku and Kakashi
Muu --- Not only because he was a Tsuchikage but also the possessor of Dust Release, being able to go invisible hiding everything including his chakra. But also his attitude, giving praise to Gaara for being able to detect him, and not caring on how he died against the 2nd Mizukage basically being like "Yeah I killed you, you killed me, it doesn't matter" lol
Yamato --- Even though we have seen little from him in fighting wise, he possesses the the 1st Hokages ability to use Wood Release. Also he has been one of my fav. characters since he appeared in Naruto Shippuden
Kinkaku --- He is a total badass being able to survive INSIDE the Kyuubi for 2 weeks with his brother and eating the chakra meat and obtaining a portion of the power of the 9 tails. As well as being able to wield weapons of the Sage of 6 paths
Kakashi --- He has been one of my favorite characters from day 1. Being able to go toe-to-toe with God Realm and the robot? paths of pain without knowing a single thing of them and still managed to take one down with the help of Choji and his dad.