Hanma, Needlesearcher

When Hanma, Needlesearcher enters the battlefield, you may search your library for a card and reveal it. If you do, target opponent may choose to search your library for a card that shares a card type with it. If that player does not find such a card, shuffle your library, then put the revealed card on top of it.
"Diversity is not just a truism. It is the truth. — Attribution to Hanma, Famous Lasts, Vol. XCVII