Agatha of the Vile Cauldron has power 1 or greater.
Steps
Activate
Knacksaw Clique by tapping it, adding ({U} magic symbol) that can only be spent to activate abilities.
Activate
Knacksaw Clique by paying ({U} magic symbol) and untapping it, exiling the top card of an opponent's library with the ability to cast that card this turn.
Repeat.
Results
Exile each opponent's library.
Metadata
In 553 decks according to EDHREC.
Bracket Tag
This combo has been estimated to be Exhibition (Bracket 1+).