By drinking this essence you become free of needing any external source for your powers/skills.
*From magic that draws in mana from the environment or sword skills that relies on esoteric or strange laws none of your abilities will require anything outside of yourself.
*This does not give you more power or skill then you already have however. If you only able to draw upon a finite amount of power this will not change that, merely allow you to use and train it anywhere.
*How this manifests is largely dependent on the power/skill in question, magic for example might draw on a internal pool.