Pick the Brain

Target opponent reveals their hand. You choose a nonland card from it and exile that card.
Delirium — If there are four or more card types among cards in your graveyard, search that player's graveyard, hand, and library for any number of cards with the same name as the exiled card, exile those cards, then that player shuffles.

Shadows over Innistrad Remastered

Shadows over Innistrad

Target opponent reveals his or her hand. You choose a nonland card from it and exile that card.
Delirium — If there are four or more card types among cards in your graveyard, search that player's graveyard, hand, and library for any number of cards with the same name as the exiled card, exile those cards, then that player shuffles his or her library.

Because you consider only the characteristics of a double-faced card's front face while it's not on the battlefield, the types of its back face won't be counted for delirium.

If there is no nonland card to choose, and you have four or more card types among cards in your graveyard, you'll search that player's library even though you won't be able to find any cards. That library will be shuffled.

In some rare cases, you can have a token or a copy of a spell in your graveyard at the moment that an object's delirium ability counts the card types among cards in your graveyard, before that token or copy ceases to exist. Because tokens and copies of spells are not cards, even if they are copies of cards, their types will never be counted.

The card types in Magic are artifact, battle, creature, enchantment, instant, kindred, land, planeswalker, and sorcery. Supertypes (such as legendary and basic) and subtypes (such as Human and Equipment) are not counted.

The number of card types matters, not the number of cards. For example, Wicker Witch (an artifact creature) along with Catalog (an instant) and Chaplain's Blessing (a sorcery) will enable delirium.