Archetype of Imagination could be a strong sideboard card against other decks the run a lot of flying! Cool deck otherwise! +1

Liking the deck, I've actually been trying to make something similar but going for a lower CMC, and using pump to make the cards more powerful (basically my mindset disagrees with your last comment). Mimeomania -- Please Advice

Grand Arbiter Augustin IV could be interesting to work past the limit of 4 wardens, and if you have more spells that are white AND blue, it reduces the cost of those spells by 2, while also casting a free Force Spike on everything :D. It's not flying though :(

Would definately recomend favourable winds and maybe sapphire medallion.

The new Dragonlord Ojutai sits nicely on-curve after Warden of Evos Isle. Its draw power is pretty awesome; fits in nicely with the deck. More importantly, it looks cool.