Nice first stab, respectable list:) The format leans aggressive, so it's best as a control deck to lean into this in your main board. Switching stubborn denial for the other 2 fatal push is a must here, and I rather run 4 silumgar's scorn than 1 stubborn denial main. Getting two stubs main elsewhere might be feasible. Dragonlord Kolaghan is going to have a lot of gas in pioneer, I expect that card to do a lot of work. Stormbreath is a sideboard card, but a great one against white weenies and UW control. I think this deck asks to be midrange tempo control instead of long game control, so lining up your starts to put your opponent on the back foot is gas. 4 thunderbreak lets you do this, as a T3 Sarkhan into a T4 thunderbreak with counterspell back up is gas. Similar if we are dropping T4 glorybringer, prismari dragon, or gold span dragon. I think Sprite dragon could be gas, and spit fire seems maindeckable. 1-2 mutavault as a "dragon land" might help with your dragon matters cards. Crux of fate as a 1 sided board wipe is awesome, especially if you thoughtseize them early, so that like 4 in the 75. I think 1-2 dragon's hoard as soft sarkhan 5-6 lines up the plays I mentioned earliar as well and offers gas. Notice I said Sarkhan 5-6, play a playset. They offer the most busted starts, have to be attacked down by your opponents, and their are no dead copies as it cycles itself. Sarkhan the masterless is likely worth 1-2 slots. I understand 5 CMC is your choke point, but he gets a consideration at least. Crucible of the spirit dragon seems really bad. Your first couple turns are crucial for surviving an early way of aggression or setting up your plays, and if you go late your pretty gas anyway. I say test it as a 1 of and otherwise make your manabase buttery smooth to start. Compare crucible to have 1-2 field of ruin with some more basic in the deck. a little more utility, and every deck runs manlands or utility lands, it's almost never dead. All your other cards are worthy of experimentation as is:)