Underbridge Warlock

For a player to mill a number of cards, that player puts that many cards from the top of their library into their graveyard.

A player can’t mill a number of cards greater than the number of cards in their library. If given the choice to do so, they can’t choose to take that action. If instructed to do so, they mill as many as possible. Similarly, the player can’t pay a cost that includes milling a number of cards greater than the number of cards in their library.

An effect that refers to a milled card can find that card in the zone it moved to from the library, as long as that zone is a public zone.

If an ability checks information about a single milled card but more than one card was milled, that ability refers to each of the milled cards. If that ability asks for any information about the milled card, such as a characteristic or mana value, it gets multiple answers. If these answers are used to determine the value of a variable, the sum of the answers is used. If that ability performs any actions on “the” card, it performs that action on each milled card. If that ability performs any actions on “a” card, the controller of the ability chooses which card is affected.

Deathtouch is a static ability.

A creature with toughness greater than 0 that’s been dealt damage by a source with deathtouch since the last time state-based actions were checked is destroyed as a state-based action. See rule 704.

Any nonzero amount of combat damage assigned to a creature by a source with deathtouch is considered to be lethal damage for the purposes of determining if a proposed combat damage assignment is valid, regardless of that creature’s toughness. See rules 510.1c–d.

The deathtouch rules function no matter what zone an object with deathtouch deals damage from.

If an object changes zones before an effect causes it to deal damage, its last known information is used to determine whether it had deathtouch.

Multiple instances of deathtouch on the same object are redundant.