Cyber Dragon Nova [LEDD-ENB30] Common Sea Serpent if the discarded card was

if the discarded card was not "Danger

but they cannot be used as Synchro Material

you can Special Summon 1 DARK monster with an ATK of 1500 or less in face-up Attack Position from your Deck

You can only use this effect of "Knightmare Cerberus" once per turn

Cyber Dragon Nova [LEDD-ENB30] Common Sea Serpent if the discarded card wasSet: Legendary Dragon Decks Card type: Xyz Effect Monster Rarity: Common Attack: 2100 Defense: 1600 2 Level 5 Machine monsters Once per turn: You can detach 1 material from this card, then target 1 "Cyber Dragon" in your GY; Special Summon that target. Once per turn (Quick Effect): You can banish 1 "Cyber Dragon" from your hand or face up from your Monster Zone; this card gains 2100 ATK until the end of this turn. If this card in your possession is