Bladeback Sliver

Changeling When Faceless Agent enters the battlefield, seek a creature card of the most prevalent creature type in your library. (To seek a card, put one at random from your library into your hand.)

Target creature's base power perpetually becomes 0.

Lifelink Whenever you cycle another card, you may pay 1W. If you do, return Benalish Partisan from your graveyard to the battlefield tapped and it perpetually gets +1/+0. Cycling 1W

Lifelink When Leonin Sanctifier enters the battlefield, choose a creature card in your hand. It perpetually gains lifelink.

4U: Target creature can't be blocked this turn.

When Lumbering Lightshield enters, target opponent reveals a nonland card at random from their hand. It perpetually gains "This spell costs 1 more to cast."

+1: Up to one target creature's base power perpetually becomes equal to its toughness. It perpetually gains "This creature can attack as though it didn't have defender." −2: Conjure a card named Lumbering Lightshield onto the battlefield. −6: You get an emblem with "At the beginning of your end step, return target white creature card from your graveyard to the battlefield. You gain life equal to its toughness."

When Wingsteed Trainer enters the battlefield or attacks, conjure a card named Stormfront Pegasus into your hand.