You're definitely gonna need a Baneslayer Angel. It's an absolute must.

This deck is just begging for Akroma, Angel of Wrath and Akroma, Angel of Fury.

You're gonna need a considerable amount of ramp for these cards that are CMC 6+, but they are the best R/W Angels I can think of.

@JerichoDarkstar thanks for the suggestions! I'm tempted to replace the two forms of Akroma with Sun Titan and Inferno Titan in order to bring down the number of high costing creatures. Is that a good idea?

JerichoDarkstar thanks for the suggestions! I'm tempted to replace the two forms of Akroma with Sun Titan and Inferno Titan in order to bring down the number of high costing creatures. Is that a good idea?

23 Lands just seem like way to little for such high CMC's. Maybe try and find multiple ways (others besides Quicksilver Amulet as you already run that) to try and cheat them in. Maybe Through the Breach?

The main problem is that this deck will simply get run over before it can do anything unless it has ways to keep the board clear in early turns. Pyroclasm, Anger of the Gods, and Wrath of God all help. Lightning Bolt and Path to Exile are good for spot removal. You can also use Raise the Alarm for early blockers.

If you splash green you can ramp into Through the Breach as suggested.

I would at least sideboard Boros Charm since land destruction is a thing in Modern.

Thanks for the suggestion! I actually meant to move the Boros Charms to the sideboard, but forgot to do so. Thanks for reminding me.

You seem to be missing Lightning Helix.