Here is batch 1 of 2 of the multicolor cards, including the Commanders. I will highlight the Commanders that have [Partner] and the ones headlining a deck [Deck Commander].
Akiri, Line-Slinger [Partner]: This is quite the beater if you control a lot of artifacts.
Ancient Excavation: feeds your graveyard in one big move.
Atraxa, Praetor's Voice [Deck Commander]: This is my favorite deck (Breed Lethality). It had me at 'Proliferate.' It has all those counters cards AND Proliferate. No.1 in my list. I want all of the other decks equally. They are all No.2 to this one.
Breya, Etherium Shaper [Deck Commander]: Thopter tokens. That's awesome. If all you are sacrificing is Thopter tokens, the sacrifice effect is worth it.
Bruse Tarl, Boorish Herder [Partner]: Solid, especially on account of the Double Strike ability you can give one of your creatures.
Grave Upheaval: It's a creature in any graveyard. That's really good, and 6 mana in Commander is mid to late game.
Ikra Shidiqi, the Usurper [Partner]: An interesting twist on Lifelink, which is gained from a creature's power.
Ishai, Ojutai Dragonspeaker [Partner]: That's a lot of counters if you have many opponents.
Kraum, Ludevic's Opus [Partner]: There can be a lot of second spells in multiplayer mid to late game. Oh, and it has Haste. Strong card.
Kydele, Chosen of Kruphyx [Partner]: You only need to tap it. If you have drawn four or five cards, that's mana you can use to cast some of those cards. It's a great effect.
Kylanos and Tiro of Meletis [Deck Commander]: A 'group hug' Commander, that's a new one. It will speed up the game. I love 'group hug' effects. Why can't everyone draw a bunch of cards in an amiable multiplayer game? It's a big wall too at 2/8.
Ludevic, Necro-Alchemist [Partner]: More card draw. That's great.
Migratory Route: a good move when you are behind. If it was an enchantment and it created fewer tokens, but you got them each turn, I would like this card more. I am thinking of an enchantment like Assemble the Legion.
Ravos, Soultender [Partner]: You can get a creature out of your graveyard every single turn and it lords all of your creatures. To me, this is a very strong commander even if it's a heavy cast.
Reyhan, Last of the Abzan [Partner]: A reassigner of counters? And you may have Hardened Scales on the board? That is just great.
Saskia the Unyielding [Deck Commander]: Very nice effect. You are sitting there looking at a very strong opponent and a second strong opponent. You can attack one of them directly, and attack the other with the 'I choose you' clause. Haste is great, by the way.
Sidar-Kondo of Jamuraa [Partner]: For a moment I thought it was Banding, the ability Wizards will never ever print on a creature again. It's Flanking. Seems allright.
Silas Renn, Seeker Adept [Partner]: A reanimator outlet? I like that a lot. You are not paying the mana cost. Go wild and reanimate something ridiculous.
Sylvan Reclamation: two exiles for five mana is a fair cost in Commander.
Tana, the Bloodsower [Partner]: Trample on a 2/2 in Commander isn't great. You would have to boost this somehow to pump tokens out of it.
Thrasios, Triton Hero [Partner]: It's not about getting more lands if you are paying 4 mana to scry 1. This is a much more useful effect to find a land for a color you are missing.
Treacherous Terrain: It's a late game cast, and it is a clean way to take out one or more opponents. I like it a lot. You can't take yourself out with it, and that is what makes it such a great play. Also, it's in Green. That means you will have the mana to cast something this big earlier than players not on Green.
Tymna the Weaver [Partner]: That is one awesome effect in a table with say, four opponents. If three of them got hit, you draw three cards. You have to pay life for the card draw, and that means you need the Lifelink, and not just from this card, and you also need additional life gain in some of your other cards.
Vial Smasher the Fierce [Partner]: It does not hit you, and that's all you need to know. The weakness here is that your opponents know you are most likely to cast your biggest spell first, and that knowledge will make them want to counter your first spell.
Yidris, Maelstrom Wielder [Deck Commander]: You need to hit very early with this to make sure the Trample can put you over into direct damage. Multiple Cascades is just awesome, really awesome. I would buy this deck and put some fetch lands in it, though. After you Cascade a couple of times, the bottom of your deck will have lots of lands you need. Of course, by the time you cast this, you will have your four colors.
Abzan Charm: solid reprint. All three choices are very good choices and you are playing it in a deck with a lot of mana fixing.
Ankle Shanker: it will be much better in Commander than it was in Constructed.
Artifact Mutation: hold it until the mid game to take out a bigger artifact and maximize how many tokens you generate.
Aura Mutation: hold it until the mid game to take out a bigger enchantment and maximize how many tokens you generate.
Baleful Strix: Great reprint. In the early game, that extra card can make a big difference.
Bituminous Blast: The Cascade may be more important than the 4 damage when you are casting a 4 drop. You could cast a 4 drop that is really good with this, maybe even a Bloodbraid Elf.
Blood Tyrant: wow! that's a seven drop creature that does not end the game... oh, wait a minute, we are in Commander, we are good. This is the card you play when there are three players left, and you need to take out one of them. The other one will make sure they remove this.
Bloodbraid Elf: Iconic. Does not need an introduction. Cascade.
Boros Charm: the best charm in Return to Ravnica block. A great reprint. The 4 damage is better in Constructed than in Commander, but it is still 4 damage, and it's to a player.
Bred for the Hunt: 'you may draw a card' is a great clause on any card. I should have played this when it was in Standard.
Clan Defiance: this is really good with a bunch of mana laying around. You can do all three!
Coiling Oracle: a classic reprint. You get to draw the card no matter what and it can even help you cast an additional land, maybe in a color you need.
Consuming Aberration: in multiplayer, this must be removed as soon as possible or else. It's 'number of cards' and not 'number of creatures.'
Corpsejack Menace: solid is solid, especially in Commander.
Crackling Doom: a strong card. Forcing your opponents to sacrifice their biggest critter is no joke.
Dauntless Escort: A solid way to avoid a board wipe, and there are some great board wipers in these decks.
Decimate: aggressively costed way to get rid of several permanents. Can you use it on multiple opponents? I think you can.