Beat mist noble under 30 seconds
Just stealth deathblow him and instantly spear him 2 times and he is finished. Easiest boss ever.
If anyone provides me a save file with mist noble I will also post a video on how to beat him easily
Edit : I just found a video of someone beating mist noble under 30 seconds here https://www.reddit.com/r/Sekiro/s/oWYt7LJI34