Gains 400 ATK for each Dragon monster you control. When this card destroys a monster by battle: You can Special Summon 1 "Wyvern Token" (Dragon/LIGHT/Level 1/ATK 400/DEF 400). During the Battle Phase or Main Phase 2, you can (Quick Effect): Immediately after this effect resolves, Tribute Summon 1 Dragon monster face-up. You can only use this effect of "Guivre" once per turn.