Knowledge Exploitation

This cards was originally printed with the "tribal" card type. That card type has been replaced with "kindred". This change does not affect the gameplay function of this card.

Kindred is a card type that allows noncreature cards to have creature types. For example, Echoes of Eternity is an Eldrazi (although not a creature) while on the battlefield and an Eldrazi card (although not a creature card) in zones other than the battlefield.

While it appears only on cards that already have other card types, kindred is a card type and will be counted by effects that refer to the number of card types among cards in a zone.

You cast the instant or sorcery card as part of the resolution of this spell. It's cast from your opponent's library, not your hand. You choose modes, pay additional costs, choose targets, etc. for the spell as normal when casting it. Any X in the mana cost will be 0. Alternative costs can't be paid.

If you can't find an instant or sorcery card that can be legally cast, or choose not to find one, skip that part of the effect. Then the opponent shuffles their library.