Arcenemy is 1 vs team of players format
The person playing alone against others will have special Archenemy deck consisting minimum 20 scheme cards where you can have maximum 2 of same card.
Archenemy plays first and starts with 40 lives when other players playing against him start with 20 lives
On the beginning of archenemy’s precombat main phase, that player moves the top card of their scheme deck off that scheme deck and turns it face up. This is called “setting that scheme in motion.”
MTG blog 