All Xyz Monsters you control gain 800 ATK. Once per turn: You can discard 1 Spell, then target 1 Xyz Monster you control; Special Summon from your Extra Deck, 1 Number C monster or 1 CXyz monster, with the same Type as that monster you control but 1 Rank higher, by using it as material. (This is treated as an Xyz Summon. Transfer its materials to the Summoned monster.) If you discarded a card other than a Rank-Up-Magic Spell to activate this effect, return that Special Summoned monster to the Extra Deck during the End Phase (even if this card leaves the field).