Effective, terrain is a Feng Shui master's special skill, and it is effective when hitting anything. The specific damage depends on proficiency and RP. In Jindel Manor, only Fubuki is usually used, and the damage value is not bad. I really can’t remember the specific amount (sorry...). RP is good for using Dark Nuclear Explosion, and it’s easy to kill the boss instantly. . Of course, if you use a whirlpool-like instant death skill on the boss, it will be ineffective and will basically miss. I remember when I first came out of the Floating Continent to fight the octopus boss, the Feng Shui Master's terrain often had whirlpools, which was very depressing. Also, I personally feel that the probability of a dark nuclear explosion in the forbidden area of ??the Crystal Tower is very high in the later stage, which is very cool. Hope this helps.