When you have a Level 4 monster banished other than "Shiranui Solitaire," Normal Summon "Shiranui Spiritmaster" to Special Summon "Shiranui Solitaire" from your hand.

Then, Tribute "Shiranui Solitaire" to use its effect and Special Summon "Shiranui Spectralsword" from your Deck!

Since "Shiranui Solitaire" was Special Summoned with the effect of "Shiranui Spiritmaster," it will be banished when Tributed. This means the other effect of "Shiranui Solitaire" activates, letting you Special Summon a Level 4 "Shiranui" monster other than "Shiranui Solitaire"!

Now, use these 3 monsters on your field to Synchro Summon "Shiranui Sunsaga"!