Kayn, Collector of Aura

Pay {u}: Gain a blue aura counter. If you have
10 blue aura counters, transform Kayn into
Emperor Kayn.
Pay {r}: Gain a red aura counter. If you have
10 red aura counters, transform Kayn into
Rhaast, Destroyer of All.
Pay 2 life, {u/r}, Kayn gain Hexproof until
end of turn.