King's Field video guide E28: Seath's Armor

Getting the Seath's Armor from the 3 sealed doors, and the Blood Crown, and finish talking to the crystal in the Elf Shrine.

[@SimplyJustRandomness]

How or whar makes that door open?

[@Highphi420]

The dark sword in your possession makes you worthy and the doors are unsealed.
After defeating Necron, the sword is in the Colosseum OR Leon still has it back at his place.