Let's do this! I love Boros voltron.

Multiple attack phases:Waves of AggressionBreath of Fury + Assemble the LegionAggravated Assault + Sword of Feast and Famine

Suggest this additional add to the Sunforger package Lapse of Certainty no one EVER expects the Boros Counterspell.

Well, first things first, love it. One of my friends had a Jor Kadeen, the Prevailer equipment cat-tribal deck. You could imagine his deck title. But one card I loved seeing in his deck was Bludgeon Brawl. What's your take on it?

I see quite a bit of tutoring, and maybe like 4 cards that draw, what's your thoughts on a Sram, Senior Edificer? Kind of a worse Puresteel Paladin but it does trigger off of Gift of Immortality that one time. Can't ever have too much draw as boros.

Lastly, I don't see any recursion other than Gift of Immortality, maybe I'm a bit blind. A Elixir of Immortality might be useful here, especially with how much you can potentially tutor.

My first advice would be that your artifact count is simply too low to reliably hit Metalcraft. I would add the artifact lands (Darksteel Citadel, Ancient Den, and Great Furnace) and more strong, cheap equipment (like O-Naginata, Tenza, Godo's Maul, Sword of the Animist, Inquisitor's Flail, Fireshrieker, etc).

I've never liked Hero's Blade much, since its equip cost is so prohibitively high unless you attach it to a legendary creature.

Mirran Crusader seems both on-theme and powerful. Bastion Protector can protect your commander pretty easily. Silverblade Paladin and Duelist's Heritage give that most-sought-after keyword, double strike. Bruse Tarl, Boorish Herder and Akiri, Line-Slinger both seem really good here.

Heliod, God of the Sun and Hundred-Handed One seem a bit odd here.

Leonin Shikari and Shimmer Myr have both been disappointments to me in the past.

Scroll Rack is super handy with Land Tax, and just a good card overall...

Wheel of Fortune over Reforge the Soul obviously if you can afford it.

Careful with Sword of Light and Shadow and Sword of Fire and Ice and Sword of War and Peace. Protection from your own colors can bite you sometimes.

I didn't have much time to really make an in-depth analysis at the moment, so I'll take a little more time to look it over later, but you definitely get my +1 ;)