Adding Blue Once we have some core red cards, we can then start looking at second colors
You could even stack these on Hazel of the Rootbloom as a backup if you need to win through commander damage
On the other hand, my Izzet Spellslinger decks ends up taking incredibly long turns, either one super long Storm turn with cards like Melek, Izzet Paragon, or more recently my durdle engine deck Myra the Magnificent
Once the pairing is done, they have to send postcards to the Gen IX games to obtain them
Dedicated card sites like TCGPlayer, as well as marketplaces like eBay or Amazon, should provide you with good coverage
Shepherd of Heroes is also in the list, giving me 2 life for each creature in my party when it enters the battlefield