Play allows you to find a quick unranked best-of-one match, whilst Brawl requires you to build a deck around a legendary creature or planeswalker
Ratchet, Field Medic Ratchet, Field Medic is a great card to add to well, robot decks (more on the distinction between robot subtype and robot decks later)
It also grants Mayhem to each card youve discard until the end of the turn, meaning you can keep pitching into the yard to keep the engine going
By making it more difficult for your opponents to target your creatures, you increase the natural advantage merfolk have
Adrix and Nev, Twincasters: A lot of competition for this spot, but Adrix and Nevs ability to double all tokens, while having ward makes it notable as a strong card here
Powerful summons, such as beings like the icy Shiva or the fiery Ifrit