Sweet deck, welcome to the Izzet League!

If you are looking to improve the deck, I would cut Curse of Bloodletting , Skullcrack, Rethink and Rayne, Academy Chancellor.

The Curse only affects one player, who will then try anything to get revenge on you. You are not really an aggro deck, so you will probably get the least use out of this card. You could instead add instant or sorceries that grant double strike like Temur Battle Rage, as those not just double the damage but also raise the power of your Nivix Cyclops in the process. The same goes for Skullcrack, it only affects one player and the damage is negledgible in commander. Rethink is just straight up worse than any other counterspell for three mana, as it is only conditional. It is below average as Cancel and Counterspell are the golden standart for counterspells.

If you really want to go for an aggressive red blue build I would remove a couple of the high drop creatures you run and replace them with more cheaply costed cantrips like Ponder and Serum Visions to get more triggers on your Nivix Cyclops-like creatures. If you want to go all in I would recommend Chandra's Spitfire and Kiln Fiend aswell as Young Pyromancer. You need to streamline your deck, lower your utility creature count and put in more cheap card draw and you have a sweet blue red tempo deck. If you want to extend on the combo side of the deck, feel free to read the primer on my Niv-Mizzet deck, which is a heavy combo build.

Have fun playing and updating the deck!

Thanks for the suggestions! This deck's fairly new and it's still a work in progress. All my EDH decks are pretty much "what I have on hand" so some things are out of my grasp (sweet, sweet Serum Visions, and some dumb choices - like Skullcrack are based upon the local meta, which consists of me and the three other guys I routinely play with. It could still be cut, though. The Spitfire and the Fiend are great suggestions for how the deck's already played, so I can't wait to add them into the tweaking pile.

Why aren't you running Curiosity? It makes a very strong win combo, either killing your enemies with damage or giving you the draws to kill them.

Just drop it on your commander, and when you draw a card, you get to draw as many cards as you want to along with dealing a lot of damage.

Good question. An earlier iteration of the deck did indeed have the Curiosity instant win. And that's why I took it out. It was kind of boring. Either it's countered or you win. Having an infinite mana combo like Deadeye Navigator + Peregrine Drake at least creates, in my mind, and interesting game state that you have to think through.

Ah, makes sense. I could see why you would not want to run it.

Looks like you love drawing, have you tried Teferi's Ageless Insight ? or Pull from Tomorrow ? they seem like a great addition to your deck (or at least a chance to be tested).

See you around :)