Maze of Muertos

When this card is activated: You can add 1 "Boss Rush" from your Deck to your hand. "B.E.S." monsters you control gain 500 ATK/DEF, your opponent cannot target them with card effects, also they cannot be destroyed by your opponent's card effects. Once per turn: You can Special Summon 1 "B.E.S." monster from your hand. If a "B.E.S." monster(s) is Normal or Special Summoned to your field: Place 1 counter on it.

B.E.F. Zelos

OTS Tournament Pack 30

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.

Boss Rush

Burst Protocol

You can reveal 1 other "B.E.S." monster in your hand; Special Summon this card from your hand, then place 3 counters on this card. During the Main Phase (Quick Effect): You can remove 1 counter from this card and activate 1 of these effects;
● Add 1 "Boss Rush" or 1 Spell/Trap that mentions it, from your Deck to your hand.
● Special Summon 1 Level 9 or lower "B.E.S." monster from your GY.
You can only use each effect of "B.E.S. Derringer Core" once per turn.

B.E.S. Derringer Core

You can send up to 5 Level 10 or lower "B.E.S." monsters with different names from your hand and/or Deck to the GY; Special Summon this card from your hand, then place counters on this card equal to the number sent to the GY to activate this effect. You can only use this effect of "Super B.E.S. Metal Slave" once per turn. Once per Chain (Quick Effect): You can remove 1 counter from this card, then target 2 face-up cards on the field, including 1 "B.E.S." monster you control; destroy them.

Super B.E.S. Metal Slave

2020 Tin of Lost Memories

If your opponent controls more monsters than you do, you can Special Summon this card (from your hand). You can only Special Summon "B.E.S. Blaster Cannon Core" once per turn this way. If this card is Normal or Special Summoned: Place 3 counters on this card. Cannot be destroyed by battle. At the end of the Damage Step, if this card battled: Remove 1 counter from this card. If you cannot, destroy it.

B.E.S. Blaster Cannon Core

Maximum Crisis: Special Edition

If your opponent controls a monster and you control no monsters, you can Special Summon this card (from your hand) in Defense Position. If this card is Normal or Special Summoned: Place 3 counters on this card. Cannot be destroyed by battle. At the end of the Damage Step, if this card battled: Remove 1 counter from this card. If you cannot, destroy it. You can banish this card from your Graveyard; shuffle all "B.E.S." monsters from your Graveyard into the Deck.

B.E.S. Big Core MK-3

OTS Tournament Pack 4

If this card is Normal Summoned: Place 3 counters on it. Cannot be destroyed by battle. At the end of the Damage Step, if this card battled: Remove 1 counter from this card. If you cannot, destroy it.

B.E.S. Big Core

Crimson Crisis: Special Edition

If you control no monsters, you can Normal Summon this card without Tributing. When this card is Special Summoned, place 3 counters on it. This card cannot be destroyed by battle. If this card attacks or is attacked, remove 1 counter from this card at the end of the Damage Step. If you cannot, destroy it.

B.E.S. Big Core MK-2

Dark Revelation Volume 4

When this card is Normal Summoned, put 2 counters on it. This card cannot be destroyed by battle. If this card attacks or is attacked, at the end of the Damage Step toss a coin and call it. If you call it wrong, remove 1 counter. If this card battles without a counter, destroy it at the end of the Damage Step.

B.E.S. Covered Core

When this card is Normal Summoned, put 3 counters on it. This card cannot be destroyed by battle. If this card attacks or is attacked, remove 1 counter from this card at the end of the Damage Step. If you cannot, destroy it. Once per turn, during your Main Phase, you can change 1 face-up Attack Position monster your opponent controls to face-up Defense Position.

B.E.S. Crystal Core

When this card is Normal Summoned, put 3 counters on it. This card cannot be destroyed by battle. If this card attacks or is attacked, remove 1 counter from this card at the end of the Damage Step. If you cannot, destroy it. Once per turn, you can remove 1 counter on this card to destroy 1 Spell or Trap Card on the field.