Deck is here: http://deckbox.org/sets/430351

This is my first commander deck, so feedback here or as comments would be greatly appreciated!

Thanks in advance!

I mean it looks good enough. First question being, who is the general? I'm guessing one of the Nivs... but which one?

Second, Izzet Chronarch strikes me as being a more expensive Archaeomancer for what it's worth.

Third, if you're running original Niv as your general, Curiosity equates to an instant win if you put it on him. Kind of a dick move, but effective depending on how competitively you play.

Fourth, nothing other than Ral grants extra turns?

Fifth, why not use some lower CMC dragons, i.e. Slumbering Dragon, with Call to the Kindred to try and cheat some of the other dragons out?

Sixth, while you are going to be sitting on the biggest creatures with evasion, you might not need it often, but things like Favorable Winds or even Door of Destinies can be quite useful.

Lastly, I've found that U/R often lacks quite a bit with regard to solid removal options. If a creature is out of burn range, you can't do much to it other than try to counter it. Why not toss in some added unsummon effects (Temporal Adept is Unsummon on a stick) and some creature counters (I'm thinking both Essence Scatter and Essence Backlash).