The Bacterium Empire Series are the main bosses in Konami's Gradius video games. "Big Core" serves as the standardized design, with every other ship following the same principles: A central power core protected by a set of ablative barriers. Sometimes following a famous on-screen prompt to "SHOOT THE CORE!", the player'sship must destroy the barriers, then the power core, in order to defeat the boss, all while dodging enough weapon's fire to typically fill the game screen. "SHOOT THE CORE!" or the variation "DESTROY THE CORE!" has become something of a catch-phrase among fans of the game.
In the case of this card, the barriers and cores of Big Core MK-II are only vulnerable when it opens its "wings" to fire lasers.
As the name implies, this card is an upgraded version of "B.E.S. Big Core".
This is the only "B.E.S." monster that does not gain counters when Normal Summoned. This seems to be by design, as it is also one of the only "B.E.S." monsters that gains counters when summoned through "Boss Rush".