Card Errata:Boss Rush

Old Lore: The controller of this card cannot Normal Summon or Set. During the End Phase of the turn that a monster on your side of the field that includes "B.E.S." in its card name, or is named "Big Core", is destroyed and sent to the Graveyard, you can Special Summon from your Deck 1 monster that includes "B.E.S." in its card name, or is named "Big Core".

New Lore: You cannot Normal Summon or Set. During the End Phase of the turn that a "B.E.S." monster or a "Big Core" is destroyed and sent to the Graveyard, you can Special Summon 1 "B.E.S." monster or 1 "Big Core" from your Deck.