Three colors also give you a good spread of Lessons to select from, and its even possible this deck wants to play no basics and splash Containment Breach or Confront the Past off additional Pathways
Most notably, if a triggered ability asks you to pay a cost (such as that of Leyline Tyrant), you pay that cost for the copy if you wish to have it paid
Your deck will have a healthy number of colorless cards to dodge your own Ugin minus, and eight mana is the key number to make with seven lands, one of which is a Shrine of the Forsaken Gods
A card like Augury Adept grants devotion of 2 blue and 2 white, but that 1 colorless mana does nothing
Triple Triad Triple Triad is a super durdly card with a high failure rate and a tough mana cost
Deathtouch is common, but watch out for more elaborate options