Gisela EDH

Detention Sphere wouldn't be castable (or legal) since it has blue in it. Was that supposed to be Banishing Light maybe?

You have no firebreathing, no red instants, and really only Pyrohemia for a mana dump, which means I'd bet 99% of the time mana from Braid of Fire won't be useable. It's a super cool card, but the deck really has to be specific for it to work. I ran it in Lyzolda, a deck with a low cost commander with an activated repeatable ability and even there I didn't get enough use out of it to run it. Here it's almost never going to work.

Outpost Siege is one of the best draw spells available in Boros. I'd be tempted to find a slot for Staff of Nin, too. There's just so few options in your colors, and you need them all imo.

It's not the most budget-friendly card in the world, but Scroll Rack is amazing in white decks. First it kinda subs as draw, but secondly if you happen to have Land Tax out you can put the extra lands back on top for new cards, then re-shuffle next turn when you use land tax again. And you already have Enlightened Tutor which will fetch whichever of the two you currently don't have out.

You've got enough permanents in this deck that Nykthos Shrine to Nyx would do good work, maybe even more than Serra's Sanctum.

IMO Flamekin Village is worth a shot. Giving big-ass beaters haste in a way that's hard to remove is almost always worth the land coming into play tapped one time. Same with Slayers' Stronghold.

Not much downside to running Shinka, the Bloodsoaked Keep, either.