White Sun's Twilight (Promo Pack) [Phyrexia: All Will Be One Promos]

You gain X life. Create X 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and
"This creature can't block." If X is 5 or more, destroy all other creatures. (Players dealt combat damage by a creature with toxic 1 also get a poison counter.)