潜行する密偵セイン is a Weiß Schwarz card from なのはStrikerS NS/W04-063. Compare listings from Singapore Weiß Schwarz sellers on CardJio, then jio them on WhatsApp.
【AUTO】 ［② Return this card to Hand］ When another of your Characters become REVERSE in battle, if this card is in the Back Row, you may pay the Cost. If you did, return that Character to Hand.
This card was printed in Japanese only; the English text above is an unofficial community translation.