Stall Until Arcane Bombardment "Lock"
Once you have Bombardment on board and instant's in hand, the game is close to locked down.
Especially if you get counter-magic exiled with Bombardment. Then, any instant in hand is also counter-magic (albeit once per turn).
Win-Con
Depending on the exact build, the wincon can vary. Sometimes a single Teferi is enough. I've also experimented with a few Kayla's Command. They double as a decent early game play and as a win-con when exiled with Bombardment.
Decking Yourself
Decking yourself is a real issue. Witness the Future or Devious Coverup can prevent the issue, once you get one exiled with Bombardment.
Other Colors
I've tried UR, BR, and BUR versions of this deck. But the board wipes in white kept bringing me back to WBR. Otherwise you end up relying on Burn the House Down or similar. (Side note: Burn the House Down makes a nice win-con). The life gain in Union of the Third Path, Sunset Revelry, and Kayla's Command have made for decent stalling too.
Improvements
There's definitely room for improvement. I don't have many wildcards in Arena, so the landbase could be improved with better duals, etc. Better spot removal such as Fateful Absence or The Wandering Emperor could be solid. Different counter magic can be better. Slimmer spells such as Make Disappear can be good. An Offer You Can't Refuse can be fun since you can target your own spells exiled with Bombardment you don't actually want to cast. (e.g. Multiple Board Wipes).
Thing's I wouldn't change
Consider and Thirst for Discovery smooth hands nicely, trigger Bombardment easily, and eventually add up to card advantage. Depopulate wipes the board for 4 mana. Hard to beat. Even in cases where they only have one creature, removing a Sheoldred for 4 mana isn't bad.
