The Scry Cannon
Alibou, Ancient Witness is one of my favorite commanders, heading a deck which is aggressive, fast, and allows you to plan your next few turns in advance. Boros sometimes struggles with card advantage, but the scrying that Alibou provides means that while you aren't necessarily drawing more cards, you are drawing the right ones. Win-Cons are combat damage, Alibou's laser cannon, and using scrying to stack the top of your deck for Saheeli's Directive. There are a lot of fun synergies to be found in the various parts of the deck, and the ability to stack the top of your library makes for interesting gameplay.
Notable Cards
**Steel Overseer ** This card is everything the deck wants it to be, It's an artifact creature which taps itself, and buffs every other artifact creature you control. It combines well with Hangarback Walker, and can make its death trigger stronger.
Hangarback Walker It's a pretty simple card, and does a lot of work in this deck.It can be dropped early to trigger Alibou as soon as you play her, or just to be another tapped artifact to power up her laser. Late game, it also can be a large creature that's hard to interact with in combat. Your opponents don't want to kill it. If they do, the swarm of thopters it makes are great for charging Alibou's laser.
Etched Champion A small, but extremely useful and resilient creature in this deck. It can almost always attack safely in order to trigger Alibou's laser cannon, and it can also serve as a wonderful blocker.
Champion's Helm One of my favorite pieces of protection for Alibou. Since Alibou gives all of your other artifact creatures haste, i've found that cards like Swiftfoot Boots or Lightning Greaves slightly mitigated in their usefulness. The +2/+2 is relevant in this deck, as going into combat to trigger the laser cannon and scrying is vital. However, Greaves and boots are still good, so if you're playing in a removal heavy meta, they might be worth running.
Mystic Forge Ideally when the laser cannon is functioning, you're able to stack the top cards of your deck, which means that you can scry artifact cards on top of the deck to play with Mystic Forge.
Saheeli's Directive As I mentioned earlier, Saheeli's Directive is one of the win-cons of the deck, and it synergizes with Alibou wonderfully. You can use Alibou to stack the top of your deck with nothing but artifacts that you can hit off of the directive. Alibou also gives any artifact creatures you control haste, meaning that Artifact creatures brought out by the Directive can attack immediately and trigger the laser cannon. Lastly, because Saheeli's Directive has improvise, it allows you to tap artifacts you normally couldn't, which in turn grows Alibou's laser cannon when your creatures attack.
Myr Battlesphere Myr Battlesphere is already a great artifact creature, but combined with Alibou, it deals a lot of damage very quickly. It creatures four Myr that it can tap on attack, which help charge up Alibou's laser cannon. Between the Battlesphere's attack trigger and Alibou's trigger, an attack with Myr Battlesphere does nine damage wherever you choose.
Combustible Gearhulk This is a pet card of mine, You can scry high CMV cards to the top and then play the Gearhulk, meaning that if your opponents choose to the take the damage, you can guarantee that it'll hurt them. In addition, Alibou can put a lot of pressure onto opponents life-totals, meaning they might be less likely to gamble, and let you draw the cards, which is a nice source of card advantage to be gained. It is admittedly tricky to pull off well, but It's an interesting puzzle to try and set up the top of your deck with this card.
Mycosynth Lattice This card will often do some interesting things in this deck. With it, every tapped permanent you control charges up the laser. With Mycosynth Lattice that the Laser cannon can become an massive threat to other players life totals. It also makes Bronze Guardian and Construct Tokens extremely huge.
Sunforger Sunforger is a great equipment in the Boros colors, and in this deck we get to run it with artifact synergies. I usually try to equip this the turn I play it, and have the mana to unequip it using it's ability. That way it's immediately able to protect itself and your board. I have a total of nine targets instants for Sunforger in the deck, though there are plenty of other targets that would work well with it, such as Return to Dust, Chaos Warp or Deflecting palm.
Phyrexian Rebirth Phyrexian Rebirth is fairly expensive at six mana, but it perfectly sets up for the next turn. Most of the time after playing rebirth, you want to replay Alibou, and then get to firing the laser cannon by attacking with your recently created and horrifying horror token.
Reforge the Soul It can definitely be a bit of a pain to draw reforge the soul in your opening hand, but using Alibou to plan ahead and plan to pay the miracle cost of the card makes it a great way to refuel your hand.
The Lands
Artifact Lands
Rustvale Bridge, Great Furnace, Ancient Den, Darksteel Citadel, Treasure Vault, and Power Depot are the artifacts lands that you're able to run in Boros colors. Artifact lands are immensely useful in this deck, as they alongside your mana rocks will often form the bulk of your tapped artifacts to charge up the laser cannon. They also work with any other artifact synergies. If wizards prints more artifact lands in Boros colors, they'll likely be going into this deck, as they are among the best lands you can draw.
Artifact Creature Lands
Inkmoth Nexus, Blinkmoth Nexus and Mishra's Factory All essentially do the same thing, you can pay one mana into them in order to make them into an artifact creature, which is useful for triggering the cannon and also just to become tapped artifacts to charge up the laser. You can tap these lands for the mana that pays into them becoming artifact creatures, so if you have an extra mana or two, you can use them to help charge up the cannon.
Notable Exclusions
Ghirapur AEther Grid and Lodestone Myr Both of these are great in theory in the deck: they tap your artifacts that couldn't normally be tapped, and so would help charge up Alibou's scry cannon. However, I found their payoffs were a little lack luster, Lodestone Myr is too small a creature for the mana cost, and Aethergrid only does minimal damage. They could be be better in other versions of the deck. Builds that have ways to generate a lot of treasures or clues might use these cards to a better effect.
Embercleave, Grafted Exoskeleton and Darksteel Plate All of these are wonderful options for Alibou. Grafted Exoskeleton allows Alibou to kill someone with an Infect Laser Cannon, Embercleave is a powerful aggressive artifact, and Darksteel plate would make Alibou immune to most artifact removal. However, I personally play in a somewhat casual meta, and thus while the above cards are powerful, they're not what I use in this build of the deck.For more competitive metas, I could absolutely see any of the above cards doing work.
I may continue to expand my writings on this deck over time! If you have any questions feel free to ask!