Warrior of Immortality

The monks of the Way of Immortality are, as the name suggests, immortal. Through years of training the body, mind, and soul, they have found the way to preserve themselves from the passage of time, freeing themselves from death unless by their enemy's hands. This is a feat rarely achieved, and with the years of wisdom these monks obtain, they often are advisors to countless amounts of leaders. 

Immortality

At 3rd level, when you choose this subclass, your body is preserved from the flow of time, and your soul is very rebellious to death. You gain the following benefits:

You cannot die of old age, and your body stays the same age it was when you take up this subclass. 

You have advantage on death saving throws.

Healing you take when under half health increases by 1d6 at 3rd level, 1d8 at 6th level, 1d10 at 11th level, and 1d12 at 17th level.

When you drop to 0 hit points, you can choose to drop to 1 instead. You can use this feature once, and cannot use it again until you take a Long Rest. 

Extend Life

At 6th level, you gain the ability to heal yourself, moving yourself farther from death's grasp. As an action, you can choose to remove 1 disease from yourself or heal by 2d8 hit points. 

The hit points healed increases to 2d10 at level 11 and 2d12 at level 17.

Immortal Aura

At 11th level, your immorality spreads itself around you, blessing others with a fraction of it. You gain the following features:

People around you for more than a week start to decrease in their aging. For every 10 years they age, their body only age 1 year, and their average life span is increased by half. 

You can use Extend Life as a bonus action, and you can choose to heal a target 15 feet near you instead of yourself, or remove all diseases from the target or yourself. 

Reverse Death

At 17th level, you can literally reverse your death. As a reaction, when you die, you can choose to instead spend 2 focus points to revert to full health. You cannot take any action, bonus action, or reaction on your next turn. You can cannot use this feature again until after a Long Rest.