If the level of the person who made the greatest contribution is higher than the level of the raid monster by 3 or more levels, then the probability of dropping an item or adena will decrease. If the level difference is nine or more levels, then, the monster will not drop any item or adena.
Raid Boss - Level
The oldest son of the Von Hellman Family that was exterminated for treason. He was a superb warrior, but killed along with his whole family before he could shine. Through a contract with devils after his death, he became alive again as a vampire, and has wandered about in the Forest of the Dead even now, dreaming about his revenge.