A full BT build with a Chikage is the most powerful build in the game. The reason is that you can get about 600-800 (depending on the gems you use) AR full bloodtinge with that weapon and it's fast. Also there are only a few enemies resistant to BT in the game so basically you won't really need another weapon.
The awesome thing about that build is not only you do an insane amount of melee damage but also high damage with guns (Evelyn 1 bullet, Repeting Pistol slightly more powerful but uses 2 bullets) and you can also use Simon Bowblade for another ranged option that is completely broken in certain situations.
Isn't Saw Cleaver build with 50STR and 50Skill most powerful? I remember it having the highest DPS with those stats.