If this card is Normal Summoned or flipped face-up: You can banish 1 "Lightsworn" monster from your hand or GY; banish 1 card on the field. Once per turn, if your other "Lightsworn" monster's effect is activated: Send the top 3 cards of your Deck to the GY.
Set Ryko face-down and let your opponent attack into it to trigger its banishing effect.
Lightsworn decks do a lot of milling so you will almost always have Lightsworn monsters to use as a cost for Ryko’s effect. Alongside other Twilightsworn monsters, Ryko can help set up Punishment Dragon’s summoning.