Red for his firebending and rage, Black for his ambition and exile, and White for his eventual turn to justice and honor
A Heart of Kiran played on turn-2 can easily be crewed by Greenbelt Rampager, Thrashing Brontodon, Rhonas, Steel Leaf Champion, and Merfolk Branchwalker that gets a +1/+1 from explore
Didgeridoo is a laughably bad card on its face, and it gets even worse when you put it into context
It has no impact on the card outside of the time it is being put into play
Even in a fully tribal deck, there's often one or two utility creatures outside the clan, and this shapeshifter can either add to our expected team, or guarantee a specific one of those outsider utility creatures
Haliya, Guided by Light Adding artifacts to trigger the Soul Sister Haliya, Guided by Light is one great thing, but that easy end step trigger is how we know white card draw can keep up with the other colors