Your opponent cannot target "Mitsurugi" Ritual Monsters you control with effects of monsters that were Special Summoned from the Extra Deck. You can target 4 "Mitsurugi" cards in your GY, except "Mitsurugi Sacred Boundary"; shuffle them into the Deck, then if your opponent controls a monster, make them Tribute 1 monster they control (their choice). You can only use this effect of "Mitsurugi Sacred Boundary" once per turn.