You can send 1 other card from your hand or field to the GY; place this card face-up in its owner's Spell & Trap Zone as a Continuous Spell, and if you do, Special Summon up to 2 "Winter Raven" monsters with different names from each other from your Deck, except "Mart, Knight of the Winter Raven". When a monster declares an attack and this card is a Continuous Spell: You can target 1 "Winter Raven" Monster Card in your Spell & Trap Zone; Special Summon it. You can only use each effect of "Mart, Knight of the Winter Raven" once per turn.