Card Rules: Rulings powered by The Netrep API. [Re: Barrel Behind the Door] You can activate 'Barrel Behind the Door' against 'Jigen Bakudan'. You don't activate 'Barrel Behind the Door' when the Flip Effect activates, you activate 'Barrel Behind the Door' when 'Jigen Bakudan' activates its effect during the next Standby Phase to inflict damage. [Re: My Body as a Shield] 'My Body as a Shield' can only be used against effects that will destroy monsters at that time. So you cannot use 'My Body as a Shield' when 'Tribe-Infecting Virus' is summoned you can only use it in response to the activation of 'Tribe-Infecting Virus''s effect, at which point the effect of 'Tribe-Infecting Virus' is negated and 'Tribe-Infecting Virus' is destroyed. Also, you cannot use 'My Body as a Shield' against cards whose effects will not destroy a monster right away, so you cannot use 'My Body as a Shield' against 'Jigen Bakudan', 'Ekibyo Drakmord', 'Magical Hats', 'Steel Scorpion', 'Toon Monsters', 'Thunder Nyan Nyan', 'Gradius' Option', 'Summoner of Illusions', 'Limiter Removal', 'Call of the Haunted', 'Premature Burial', or 'Autonomous Action Unit'. [Re: Prime Material Dragon] 'Prime Material Dragon' can only be used against effects that will destroy monsters at that time. For example, you cannot use 'Prime Material Dragon's' effect when 'Dark Armed Dragon' is Special Summoned you can only use it in response to the activation of 'Dark Armed Dragon's' effect when it targets a monster. Also, you cannot use 'Prime Material Dragon's' effect against cards whose effects will not destroy a monster right away, so you cannot use 'Prime Material Dragon' against 'Jigen Bakudan', 'Ekibyo Drakmord', 'Magical Hats', 'Steel Scorpion', 'Toon Monsters', 'Thunder Nyan Nyan', 'Gradius' Option', 'Summoner of Illusions', 'Limiter Removal', 'Call of the Haunted', 'Premature Burial', or 'Arutonomous Action Unit'.