Both of these are worthy of being a three-mana spell on their own, but having them both on one card makes this a great card against a lot of different decks, and you can play it without worrying about what it is your opponent might be doing
Technically, Mica, Reader of Ruins from Secrets of Strixhaven, is also responsible for a small uptick in play
Unsurprisingly, unless you absolutely adore every card included within the MTG Arena precons, we dont recommend you buy them
Old Gnawbone is a big dragon that can generate absurd amounts of mana, and this deck is so good at drawing cards that it could enable some truly heinous sequences where you cast multiple huge creatures in a turn, resulting in Eshki eliminating multiple opponents
The Water Crystal is a mill players dream