Lord Ruthven, the vampire king, and the boss of the Manor of Immortals (which is dropped by Kage Kami or can be bought for 125 realm gold). . He has two phases, when you first activate him he will starting shooting yellow bullets that can do 100 DMG (If you have 0 DEF) then he will become invulnerable for a little bit then shoot four bombs that actually drop coffins which when destroyed or waited for long enough will spawn 2 Lil' Feratu. Then Lord Ruthven will spawn a ton of bats, you have to shoot the right bat that the boss turned into. Then the phases repeat till you kill him.
heal: He is a hard boss with 12,000 HP
Damage: 100 DMG
Go with long range classes, or with strong tank classes. I prefer Long range calsses.