As it's owner, your soul is forever tied to The Death House granting you a Dark Gift. You can reach it via a portal or summon the entire manor and its occupants to another plane of existence. The house also protects you from dying. You gain the following abilities when you receive this Dark Gift:
Eternal Servant - Your soul is forever tied to the house. If you die (fail all 3 death saving throws), your body is automatically transported to the alter of the manor's Ritual Chamber and become stable at 0 hit points. If your body is destroyed while on the alter or while upon a different plane from the manor there is a 50% chance this resurrection fails. When this ability is triggered make a new Death Saving Throw. On a success your body returns and becomes stable at 0 hit points. On a failure, you return as a Shadow, cursed to forever haunt the halls of Durst Manor until a new owner is chosen.
Doorway Home - As an action you can turn any normal doorway into a portal that leads to the portico of Durst Manor. The portal remains open for 1 minute. Durst Manor must be on the same plane of existence as you. You can return to the last location you came from (as long as it is still on the same plane of existence) with an action by touching the portico gate from the inside. Once you've used this ability you can not do so again until you finish a long rest.
Call the Manor - You call Durst Manor and all of its current occupants to your location, even if you are on a different plane. The location must have enough flat open ground for the house and it's grounds or the summoning fails. The basement is an extradimensional space so is not figured in the space needs. The house can be returned to Barovia at any time and does so automatically if the house if ever burnt down or destroyed.
The Walls Have Eyes - You learn the Scrying spell and can cast it at will on any area within Death House while within one mile of its current location. This spell uses your Charisma as your spellcasting ability.