When should we fight Takezo the unrivaled
I believe that Ghost of Yotei, much like Ghost of Tsushima, was designed to have one last battle after the final boss fight. In Ghost of Tsushima, Jin has to fight his own uncle, Lord Shimura, but as the story in Ghost of Yotei goes, everything feels very rushed. Atsu has to hurry to save Jubei and Oyuki, so the story is essentially telling us to not do anything else and just focus on helping them. This is why the confrontation with Takezo is a side mission; it’s not meant to interfere with rescuing your brother and friend.
Ideally, you should fight Takezo during one of two periods. The first is at the end of Chapter One (after you finish off Kitsune and the Oni), if you feel you are ready for the challenge. The second, more fitting time is at the very end of the game after you have rescued Oyuki and Jubei. By this point, your skill set and all of your weapons should be fully upgraded.
However, the game still gives the player the freedom to fight Takezo at any time they choose.

