Essence of the Immortal:

By consuming the Essence of the Immortal, the quintessence of the desire to live forever, you gain the following boons:

* Your ageing halts when you reach the prime of life, the exact moment when the body stops maturing and starts dying. If your body is already past the prime of life, it reverts to that point.

* A healing factor that maintains you in perfect health and lets you rapidly recover from any injury, disease, or poison short of the total destruction of your body. You can easily block out pain if you want to while still retaining an awareness of injury.

* Perfect memory with infinite storage and data recovery. Even if your memories are somehow erased, they will eventually return. Death of identity is just another form of death, and you can never truly die.

* Skills, stats, and abilities never degrade due to lack of training or the passage of time. Reincarnating into a new body does mean you have to physically condition that new body from scratch, but 'muscle memory' is actually in the mind and so carries over just fine.

* An indestructible mind, that is highly resistant to insanity and which will eventually recover from any amount of mental trauma or destruction even if crushed or obliterated by overwhelming force. Barring other powers or abilities you can still potentially be negatively affected by horrible events, boredom, sensory deprivation, etc., but you will never be permanently lost inside your own head.

* An eternal soul, that cannot be trapped, bound, owned, permanently harmed, or eliminated by any power short of the Supreme Being. If you are ever destroyed by any means, up to and including being retroactively erased from having ever existed, you will reincarnate somewhere else and regain your memories and abilities in early childhood. Barring other factors you will reincarnate on the inhabitable world closest to where you 'died' as a healthy newborn of the closest equivalent to the race you 'died' as, usually the same one in both cases. If the entire universe is unavailable to reincarnate in then you will reincarnate in a nearby universe.

* The ability to voluntarily 'die' and trigger your next reincarnation. Intended for use in situations such as being trapped in an inescapable void, buried underneath a collapsed mountain, being devoured alive for eternity in an Elder God's stomach, locked in temporal stasis, trapped in an inescapable time loop, etc. This ability will never activate under any circumstances unless you genuinely and of your own free will want it to, but can be activated 'subconsciously' regardless of how incapacitated you are.

* The ability to petition the Supreme Being to end your immortality and allow you to move on to what comes next, but only if you while entirely in your right mind and with the utmost sincerity want to.