By consuming the warm, iron-tasting beverage, you gain the power to sacrifice.
*You possess a personal pool of sacrificial power, that can only be replenished through sacrifices of some kind. This pool grows as you use it, and leftover ritual magics seep into your essence to beneficial effect -- including improved affinity with the powers of this essence. The sacrificial power of your pool can be expended in nearly any way, though only through suitable rituals, whether it be summoning beings across the void, conjuring wealth, acquiring immortality or even granting a slightly limited version of this essence to others. These rituals may even endow you with abilities that can be freely used, or work through contingency-style effects activated by set triggers. It highly favors body transformation or augmentation effects, flesh and blood, as well as curses, being a fair bit less efficient in other domains.
*Sacrifices are the destruction of something of significance, in a permanent manner. Things sacrificed cannot ever be restored naturally, nor even by most supernatural powers, though this essence can do so at a net loss. Anything that belongs to you can be sacrificed as is, however sacrificing the things of others requires manually destroying them. This generates the required sacrificial power to use this essence, and any excess is wasted, or vented into your body in beneficial ways that start out minor and slowly build up over time. This is not taking into account external artifacts -- such as the creation of empowered items to serve as batteries.
*You can become a Sacrificial Idol by having others perform sacrifices in your name, enabling them to use the power of this essence through you as a middleman. This allows you to take a toll of sacrificial power from any of their sacrifices, bolster your own ritual power and slowly gain subtle control over them. In turn, they would be able to perform the rituals you allow, loan sacrificial power from you and gain your favor in the form of endowments, new rituals or bestowed sacrificial capacity. As your Idol status grows you gain various abilities revolving around augmenting or granting new ways through which to expand on your power of your followers and this essence. At its base you can sense your followers and hear when they speak your name, as well as remotely perform rituals around them, whether to their benefit or detriment.
*You possess an entire mental library and framework in your mind, with a large collection of every conceivable basic ritual you could desire, and the ability to easy build more on the same framework. These rituals are special and are many times more efficient in terms of sacrifice as opposed to freeform and 'normal' rituals that others may use, though they can also be taught and/or improved further.