1 Tuner + 1+ non-Tuner DARK monsters
If this card is Synchro Summoned: You can add 1 card that mentions "Red Dragon Archfiend" from your Deck to your hand. When your opponent activates a monster effect (Quick Effect): You can banish this card you control; Special Summon 1 "Red Dragon Archfiend" from your Extra Deck (this is treated as a Synchro Summon), and if you do, its ATK becomes doubled, also it cannot be destroyed by your opponent's card effects. You can only use each effect of "The Crimson King" once per turn.