This is such a captivating and powerful piece of two different energies fighting over the dominance and the place for the strongest and coolest bird in the sky!
I'm really liking the Thunderbird (Blue is my favourite colour, so I'm totally biased here!) and how life-like the lightning looks coming from within the bird. The Phoenix looks cool as heck and I really like the cloud of ash, flames and sparks behind it.
Those small bits of fire look like burning feathers.
I really adore the detail work on both of the birds' plumage and how the electric is traveling as a blue light in-between the Thunderbird's feathers. The Phoenix's wings look almost metallic! It must've been training those feathers with all of the burning stuff its doing so much, that they've become steel-plated and battle hardened.
Yet you can still tell that the feathers are delicate and soft.
All epic air fights must be fought in the mountain view because mountains are beautiful, enigmatic and cool as hell in the background!
So that is a really good choice for the background! All in all: this is an awesome piece of art!