Be sure to find the businessman in every place, the one who wants you to take a message home. When you find all seven, you can exchange old books for building materials from him, and you can save them every time you trade. If you don't want to repeat it or not, you can read it again.
Experience: patience, patience, patience again.
I suggest, just make it for Cai Xin, the others are too weak.
For example, Liang Hu, the hidden equipment is absolutely abnormal, and it will not lose blood if it is built. Nie Gai, this hidden equipment has exorcism attribute, and this monster will definitely save his life in the later period, because in the maze before the final BOSS war, the small broken soldiers are super awesome when adding attributes.
Wei Lan, in the enchanted cannibal forest, made her equipment for cannibal flowers, and let her suck blood, so that she could fight a protracted war in the later stage (the fire system was not strong in the later stage, because most of the terrible monsters were water systems, and if one third of her blood was consumed, Wei Lan would be dead ... and then there was "Hero, please start over".
Hong Yan, if you give him a set of bats in the imperial tomb, it's like hitting a chicken when you hit Chiyou. Because an important attribute of the equipment is that the freezing attack is increased by 20%, plus the main water system of Hong Yan, his freezing attack can reach 40% of the division of labor (of course, you have to play better). Playing BOSS is about drinking tea.