For now, the only existing and available subtype in March of the Machine is Siege
Unlike the slow and methodical decks where Urza will likely fit best, Mishra and his melding counterpart, Phyrexian Dragon Engine, are designed to support aggressive strategies that aim to beat opponents down to a pulp
It never plays favorites
My booster box isn't going to have every card, and there will be lots of duplicates, so I'm guessing I'll be using a lot of the cards I open
Primarily focusing on budget EDH content
Liliana Vess allows the player to force their opponent to discard cards, allows them to search their library for a specific card, and can return all creatures in both player's graveyards to the battlefield under their control, flooding the board with creatures for a huge swing, which will often lead to the end of the game