Arhat Fist is a new unique jianghu style that is extremely good one on one. It’s an external fist style that has a lot of chase and significant damage. However it is extremely rare to find ruined books to assemble unless you make use of a new npc and special drops from very difficult forbidden instances.
With the new Mount Hua expansion there are now unique items that drop from boss loot reward screen during forbidden instances.
These are break weapons. They drop in groups of 2-6 from at least Twilight Villa Shura mode, Green Cloud Castle Shura, Peacock Villa Normal – Shura, Longman Inn Normal – Shura, and Yanman Pass Normal – Shura.
With these Break Weapons you can go to a special npc in Chengdu named Mysterious Man.
For 5 of your Break Weapons he will give you one bound Arhat Fist Ruined Book
From here it follows the same method as the normal ruined books in that you need 10 to assemble into one full page and you get a random 1-6 page.
Get to running those instances and maybe you too can be the first to unlock Arhat Fist.