When Mindwrack Demon enters the battlefield, put the top four cards of your library into your graveyard.
Delirium — At the beginning of your upkeep, you lose 4 life unless there are four or more card types among cards in your graveyard.
4/8/2016 Mindwrack Demon’s delirium triggered ability does not include an intervening “if” clause. This ability triggers at the beginning of your upkeep regardless of the number of types in your graveyard, and it checks that number as it resolves to determine whether you lose 4 life or not.
4/8/2016 The card types in Magic are artifact, creature, enchantment, instant, land, planeswalker, sorcery, and tribal (a card type that appears on some older cards). Supertypes (such as legendary and basic) and subtypes (such as Human and Equipment) are not counted.
4/8/2016 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.
4/8/2016 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.
4/8/2016 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.