Blight is a keyword action from Lorwyn Eclipsed. To blight X, a player puts X -1/-1 counters on a single creature they control. A player can put more counters on a creature than it needs to die.
Tokens make ideal Blight fodder. High Perfect Morcant looks outward by making opponents Blight as Elves enter, while Auntie Ool, Cursewretch rewards Blight-ing on either side of the table with cards for you and life loss for opponents.