Boss Rush (OP30-EN017) - (Common) - OTS Tournament Pack 30 Unlimited

Activate only if you did not Normal Summon/Set this turn. You cannot Normal Summon/Set. During the End Phase, if a face-up "B.E.S." monster(s) you control was destroyed and sent to the GY this turn while this card was face-up in your Spell & Trap Zone: You can Special Summon 1 "B.E.S." monster from your Deck.