A Megacore is the embodiment of the energy of an NFL Team and its community. Protecting the Megacores is one of the primary duties of the Guardians, as the Megacores are targeted by Wild Card.
A Megacore is the approximate size and shape of an NFL football. Each Megacore glows and is branded with the logo of the team it belongs to.
A Megacore absorbs and stores the energy of a NFL franchise and its fans, and is typically kept under guard near the home stadium for each team. When an NFL game is played, the two NFL Megacores of the participating teams are taken out of storage to the stadium, where they release the energy for the teams and fans to use. Offseason, a team's Megacore can be stored in a different, undisclosed location.
As each Megacore absorbs the good energy of its community, the effect of a Megacore is passive and can be felt for miles. As long as a Megacore of a participating team is in the relative vicinity of the area that team is playing in, there are no ill effects.
However, if a Megacore is taken to Wild Card's lair, it can be used to empower a BlitzBot, which increases its durability and strength. Wild Card can also absorb the energy of Megacores for both sustenance and to increase his own power.
The energy of each Megacore appears to fuel each NFL Rusher, as NFL Rusherz are the first to experience weakness once their respective Megacores fall into enemy hands. Humans also suffer long-term effects from the loss of a Megacore, as both players and fans are shown to grow weak and collapse if their community's Megacore is not present for an extended period of time.
In Mystery Solved, Megacores are revealed the byproduct of Sudden Death's attempt to merge the shards of The Core. The excess power from this incident went back to each team, which created the Megacores.