An Omnicrystal, or depending of the species an Omnisac, is a physiological feature that Pokémon have that allows them to interact with Typed Energy.

Most Pokémon (if not all) have such omnicrystals in their bodies; in the case of fully organic Pokémon, these structures present themselves as omnisacs instead. These structures or organs are dedicated to store typed energy, convert some of it into matter, and use it in attacks and moves of various types.

Omnisacs / omnicrystals are basically nodes of a particular kind of crystalline matter compressed and laid out in a fractal structure that allows it to siphon and withhold typed energy. They are organized within the body much like the lymphatic system nodes are, at least for “flesh and bones” Pokémon; whereas inorganics such as Cryogonal would have some sort of cores hosting the omnicrystals. A given omnicrystal can usually interact with in the order of 12 different Types.

The name “omnicrystal” is grandfathered from old times of less advanced research in the Pokémon world and is somewhat of a misnomer - no Pokémon are known with a singular omnicrystal that can store energy of all types; instead, most omnicrystals and omnisacs are structured to be able to siphon about twelve (12) Types. Different Pokémon species have a different number of omnicrystals or omnisacs, usually in the number of two or three, and with those they can handle much of the type chart.

The fractal structure of omnicrystals allows for quick decompression (defolding) of typed energy in large quantities given the crystal’s size relative to the Pokémon's body; this combined with the ability to turn energy into matter quickly within certain thresholds is what allows most Pokémon to perform such feats such as firing water jets that their bodies would not be able to contain in their limited volume, or materializing leaves or metal apparently out of nowhere for use in attacks.

Types that have immunities one to another, such as Fairy to Dragon or Normal to Ghost, can’t share an omnicrystal, thus defining a minimum number of omnicrysals a Pokémon needs to have in order to interact with energy of all types.

(DEVEL NOTE: This is also available to help clue in on why there are Pokémon that, across generations, just happen to not learn moves of certain types, though it still needs some extra work)

Just like with Gems, energy stored within an omnicrystal can not stay typed indefinitely - if not used, or if specifically chosen to be stored for long-term, the energy type-decays into “typeless” energy, at which point it can be defolded and distributed to other organs of the body, or it can be used in an explosive release that powers up Evolution or a Overdrive.

In certain specimens, where the omnicrystal or omnisac can extend tendrils that reach through the body over time, an explosive typed release of energy can cause the specimen to suffer a temporary, systemic Type change, a phenomenon referred to as Crystal Type.

Omnicrystals are usually well-protected within a Pokémon's body. This is necessary as due to the amount of energy an omnicrystal can contain, major structural damage to the organ can result in an explosive energy release, grievously hurting or even killing the Pokémon. There are some notable exceptions to this extreme containment rule: such as Dialga, whose omnicrystal core is actually the fin-like structure on its back (and not the chest diamond as many people would assume), or Porygon, whose omnicrystal is about as large as its beak and is contained within a folded subspace not unlike that inside a Pokéball.

The concept of an “omnisac” was ce-developed by Project PEFE as a foundation for why Pokémon can use their elemental attacks, the materialized idea being that Pokémon would have organs dedicated specifically to store energy for attacks.

• Pokémon Biology General
• Typed Energy
• Gems
• Crystal Type (see also Crystal Type)