Because the unearth ability your creatures gain is so cheap, you can get a lot back out in a single turn
To put it simply, MTG Jumpstart is a format where players use 40-card decks, which are randomly created using Jumpstart booster packs
Each of these effects is well costed on its own, so even if you can only pick one, 5-7 mana will usually ramp out your commander or another expensive spell, and effectively drawing 3 cards will usually get you to a land drop or something you can play later in the game
Following the victory over Ursula, the realm throws a party, but a cryptic map is found amid the revelry
Kiora Bests the Sea God The most expensive MTG Saga on this list, but its high mana cost is more than made up for by its litany of game-ending effects
But it's a little pricey on the secondary market, hence it's lower placing on the list