So, I've made a lot of Voltron decks, and really - almost any Commander can effectively Voltron. So far I've done
Cromat,
Tibor and Lumia,
Roon of the hidden Realm,
Purraj of Urborg,
Daxos of Meletis,
Lazav, Dimir Mastermind,
Karlov, of the Ghost Coucil,
Vaevictis Asmadi,
Jenara, Asura of War. Probably several others who I've forgotten. T&L and Daxos have probably been the most fun builds so far. I also have some experience with my brother's decks, and helping some friends build some, and some other powerhouses can include
Godo, Bandit Warlord,
Glissa, the Traitor,
Jor Kadeen, the Prevailer,
Sliver Queen (nat 7 power),
Gisela, Blade of Goldnight,
Bruna, Light alabaster,
Aurelia, the warleader, and
Thrun, the last Troll.
Everyone knows that Commanders with a natural 7 power (or able to get there) are strong for the 3 hit kill, but Commanders with a natural 5 power are also strong - a lot of equipment (
Loxodon Warhammer,
O-Naginata) give +3 power, which works well if you've hit unbuffed previously - 5+8+8 = 21. This is on top of swords bringing them to the 7 power mark as well.
Your best colors will be White and Blue, by far - Both colors give you tutoring, and recursion to an excellent degree. Blue gives you some additional copy/clone effects if you want to play with doubling up certain swords, and if you want to run time magic, some extra combats and 'haste'. Red can also be beneficial with some tutoring, recursion, and extra combat steps - plus some excellent haste sources.
White obviously gets you
Stoneforge mystic, and its budget cousin
Relic Seeker.
Steelshaper Apprentice can be great as well, because you first go get boots, then he's a 5 mana buyback tutor that can block.
Sun Titan is some obvious recursion, but I've found
Salvage Scout to be fantastic as well, since with
Sword of Light and Shadow they'll protect each other.
Leonin Shikari and
Puresteel Paladin are of course worth their weight in gold.
Marshal's Anthem is always great to bring back all of your tutor and artifact recursion guys, to get the board rebuilt again very quickly.
Reconnaissance is great to keep a defensive presence up, but doesn't work well with the pro-white swords, or sources of shroud.
If you add blue, don't forget to add
Trophy Mage, as it can get all the swords, plus things like
Loxodon Warhammer or
Sword of Vengeance, as well as your regular rocks, and
Sculpting Steel, etc.
Teferi's Veil can be hit or miss depending on your playstyle. It can be great to protect your guys and your equipment from wrath effects, but sometimes it's better to have something granting vigilance so that you can keep your guys for defense as well. I've had a lot of fun with
Phyrexian Metamorph by flashing it in via
Winding Canyons as an equippment and attaching at instant speed with Shikari.
On the red side of things, obviously there's Godo, Scrap Mastery, Daretti, Goblin Welder, etc - but two prime cards that pack a punch are
Seize the Day and
Psychotic Fury. From new cards,
Embercleave has looked like a potential interesting addition to the package. On the more fun side, I've never not had fun after dropping a
Bludgeon Brawl.
If you choose to go green, a powerful add can be
Bow of Nylea - since a lot of equipment can give trample, the combo with Deathtouch makes it very difficult to block.
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If you want to run a more combat-focused deck, but not necessarily go full Voltron, I had a lot of fun with
Power Matrix in Kurkesh.
Duelists Heritage also looks to be a lot of fun, since you can mess with other combats.
Naya has a lot of good choices, like Gahiji and Marisi, which can help speed up some aggression, while dropping to RW gives you Jor Kadeen, who's a good artifact aggro commander, that hides a vicious Voltron side.