Avara, Radiant Wordlfire

At the beginning of each upkeep, choose a color at random. Until end of turn, spells you cast of the chosen color cost {4} less to cast and have flash. Whenever you cast a spell of that color this turn, you get an Experience counter.
As long as you have 5 or more Experience counters, whenever you cast a multicolored spell, draw a card, and add one mana of any color.