March of the Machine

Skyclave Aerialist | Creature | Merfolk Scout | Flying {4}{G/P}: Transform Skyclave Aerialist. Activate only as a sorcery. ({G/P} can be paid with either {G} or 2 life.) | Michal Ivan

Gnottvold Hermit | Creature | Troll | {5}{U/P}: Transform Gnottvold Hermit. Activate only as a sorcery. ({U/P} can be paid with either {U} or 2 life.) | Artur Nakhodkin

Invasion of Pyrulea | Battle | Siege | (As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.) When Invasion of Pyrulea enters the battlefield, scry 3, then reveal the top card of your library. If it's a land or double-faced card, draw a card. | Nicholas Gregory

Mutagen Connoisseur | Creature | Vedalken Mutant | Flying, vigilance Mutagen Connoisseur gets +1/+0 for each transformed permanent you control. | Alex Brock