Daily win rewards follow a specific structure
The Precon List Before we talk upgrades, let's take a look at the stock list to see what we're working with: Despite its name, Eldrazi Unbound isn't actually focused primarily on Eldrazi: I only count 12 cards that make eldrazi, and only 1 card that supports eldrazi specifically (Eldrazi Temple)
The unofficial sites are very accurate recreations made by fans
Mm'menon, the Right Hand Maybe you made a bunch of gnomes, food, or clues, or you have an Ichor Wellspring just sitting around, Mm'menon, the Right Hand turns all of those into mana rocks, and as long as you play cards from the top of the library like it allows, or cast from exile, or the graveyard, you'll more than get your money's worth out of Mm'menon
Avengers: Under Siege rewards you for going wide with villains by producing Treasure, plus a small sweeper that ignores your boards
For a single blue mana, Illusion of Choice is an instant that not only lets you draw a card, but also lets you choose how other players vote for the rest of the turn