It's crucial to killing enemy planeswalkers or players
Sultai Arisens commanders are a tale of two stories in Kotis, Sibsig Champion, and Teval, the Balanced Scale
Gisa Tips & Tricks Keep an eye out for other cards that can boost the power of your creatures
There are enough cards that you can't really break the symmetry of, like Tombstone Stairwell and Hypergenesis, that I don't think the deck is too unfair for most playgroups
As outlined in another Reddit post commenting directly on Dominaria United Jumpstart contents, the Jumpstart alternatives for upcoming core sets can be seen as a replacement to what was Theme Booster products
Other good three-color options include the evergreen Muldrotha, the Gravetide, and Saruman of Many Colors who gets a bit of extra value from having guaranteed access to a high-cost spell in the companion zone