its just pure efficiency
G'raha Tia, Scion Reborn G'raha Tia, Scion Reborn is a great lifegain payoff, and prowess trigger, because with plenty of life, you turn those spells into decent-sized creatures for no extra mana
Do keep in mind that with 50-50 odds per coin, MAXamar does 30 damage per turn on average, so if you plan to fight with Malamar EX, its probably best to use tools that let you reflip coins
Including ways to buff Shadowfax allows you to cheat out even bigger creatures each turn
An Artifact that requires no mana to play, Black Lotus adds three mana of any color to your pool, letting you cast powerful spells rapidly in the early game
Of course if your budget allows, Summon: Knights of Round, Exalted Sunborn and Elspeth, Storm Slayer are fantastic