Kolaghans Command and Kayas Guile are flexible cards that have good colors for maximizing your All Suns Dawn and Niv-Mizzet Reborn
Answers More often than not, youll want to run utility lands to just deal with a problem an opponent has presented you with
Alongside the Ring, there were a number of Sol Rings printed in the style of the Elves, Dwarves, and Humans of the world, representing the Rings of Power forged for each race
Suppression Field If you run few or no activated abilities yourself, or perhaps you just have enough mana that you don't have to care, Suppression Field can do a ton of work for you against the likes of Abzan, Twin, Affinity, Tron, and more
The same effect can be obtained by copying the Jewel