This essence doesn't taste like anything - indeed, it is most often simply observed as something that you obviously used at some nebulous point, but don't really remember doing.
*A complete reformatting of your soul structure, making it totally independent from the metaphysical system of your multiverse, universe, planet etc.
*A partial rewriting of your existence such that you can continue to exist in places that would normally render it impossible, and basically still act as normal. You can enter a cartoon universe without yourself becoming a cartoon, travel through the ethereal realm without shedding your corporeal form and so on.
*A capacity to automatically adapt to non-maliciously hostile enviroments such that you can exist comfortably in then indefinitely, be it the depths of space or the elemental plane of fire.
*An enhanced ability to navigate the multiverse, landing precisely where you desire within a universe and within the multiverse if you don't have interference, and always knowing the exact risks of attempting to navigate dimensional disturbances before attempting.
(As noted, it's an implicit protection that most multiverse travellers effectively have, save perhaps the last bit.)