There are many special achievements in "Assassin's Creed: Visions", and the Snake Head achievement is one of them. To do this achievement, you need to open the book placement puzzle in Huabiha's secret room, from the one closest to the stairs to Farthest base: blue → yellow → black → white.
How to make the Snake Head achievement in Assassin's Creed Vision
Snake Head
The achievement requirement is to eliminate the leader of the cult
The book placement puzzle that opens Huabiha's secret room: from the base closest to the stairs to the farthest: blue → yellow → black → white
(In addition, there is a missing book in this book puzzle scene, it is strongly recommended to collect it as well)