Legendary "tribal" with Sisay, Weatherlight Captain at the helm. This is my first five-color deck, so bare with me. Essentially we want to get Sisay out, buff and protect her, and search out powerful legendary creatures or walkers and get them on the field. A simple enough premise. I wanted to make this deck as flexible as possible with the means at my disposal, so that after assessing what your opponents are doing you can decide to focus on a more aggressive or defensive mode of play.
Ramp
To ramp and fix our mana, we have staples like Cultivate, Farseek, and Explosive Vegetation to help out, plus artifacts like Sol Ring, Arcane Signet, Wayfarer's Bauble, and Chromatic Lantern are good ways to work without access to green mana. Because we have cards like the Panoramas, Terramorphic Expanse/Evolving Wilds, and Sword of the Animist, I've put in three copies of each type of basic land for a total of 15 to make the most of these cards. Furthermore, Mina and Denn, Wildborn allows you to play an extra land per turn, making it even easier to ramp. To further aid our mana needs, Kiora, Master of the Depths can +1 to let you untap one creature and one land, which is a fantastic value, followed by Wilderness Reclamation which allows you to untap all your lands in your end step. This is extremely powerful, as you can not only use this mana to respond to opponents plays but also lets you use Sisay's toolbox ability to cheat a Legendary onto the board an extra time or maybe even more times if you have the mana right before it comes back to your turn! Barring that, Cryptolith Rite lets you tap a creature for any color of mana. Not ideal perhaps, but still a useful option to have, and playing this enchantment costs very little anyway so there's little reason not to play it. Faeburrow Elder is one of the only two non-legendary creature in this deck, but since it can be tapped for whatever colors our permanents on the field have it's an easy include for this deck since we already want to get all colors on the board ASAP. The other non-legendary is Dryad of the Ilysian Grove, which not only lets us play another extra land, but also gives all of our lands every basic land type on top of their normal types. Ramp AND fixing!Neheb, the Eternal also rewards you for being aggressive by giving you red mana after combat equal to how much life you've chipped away from your opponents so far in the turn. Lastly, it would be remiss of me not to include Smothering Tithe, since it either gives you treasures when your opponents draw or otherwise forces them to waste mana to keep you from getting those treasures, both of which are values that cannot be underestimated.
Defensive Utility
This deck offers lots in the way of protecting yourself, or otherwise either slowing your opponents down or making it unappealing to attack you. Ghostly Prison and Propaganda charge your opponents two mana for each creature they want to swing your way, so getting either out early makes life difficult for them, and having both simultaneously makes it extremely difficult for them to be aggressive towards you. Blind Obedience not only slows down your opponents plays by making their creatures and artifacts come in tapped, but also gives you the options to Extort and drain their life whenever you play spells for the piddly cost of one black/white mana. Swiftfoot Boots and Darksteel Plate are fantastic pieces of equipment for protecting Sisay, so try to get them on her as soon as you can, if able. If your opponents try to wipe the board, cards like Boros Charm and Teferi's Protection are excellent cards to keep in hand for such threats. We're also running a couple counter spells just in case, and we also notably have Vedalken Orrery to let you Flash things out if you need a blocker or to make a clutch play with some other kind of permanent. To further dissuade an opponent's offensive strategies towards us, we have Gerrard, Weatherlight Hero to help bring back any other creatures that may have died on the same turn as him at the cost of exiling him, while Mathas, Fiend Seeker puts bounty counters on your opponents' creatures at the end of your turns, making it more tempting to kill off those creatures for that sweet card draw opportunity when they die. Because many of our creatures have the relevant keywords applied to them, Rayami. First of the Fallen being on the field can make it less appealing to go after those other creatures, but will likely make itself more of a target as a result. Let's also not forget Lavinia, Azorius Renegade, who is good in the early game for preventing your opponents from casting noncreatures that require more mana than their lands can provide them , making their mana rocks less useful. She also counters anything that they could cast that is done so without paying it's mana costs, which is always relevant in commander.
Card Advantage and Filtering
Probably the best card advantage engine we have here is Sisay's fellow captain, Jhoira, Weatherlight Captain, who rewards us for playing Historic cards (i.e. our legendaries and artifacts) by letting us draw a card when we do. Tymna the Weaver wants us to hit as many opponents as possible, as each one we do combat damage to allows us to pay a life for each one to draw one card each, and that's incredible value. With Sorin, Vengeful Bloodlord in play with her, you'll easily be gaining far more life than you'll ever spend for this ability. Chulane, Teller of Tales is also fantastic, as every time we cast a creature of any kind he lets you draw a card as well as put a land from your hand into play, which is even more ramp added to what was said above! Not to mention he adds to your defensive utility by allowing you to pay mana and tap him to return a creature to your hand, which can then be recast for even more value! Xira Arien is a cheap Jund card that allows you to pay Jund and tap her to draw a card, a simple but useful ability. The Royal Scions have a +1 ability that lets you loot a card and filter things out a bit if you have a dead card in your hand you'd like to chuck. You can also crack your Commander's Sphere if you really need to. Liliana, Dreadhorde General also lets you draw whenever a nontoken creature of your dies, which is another thing to dissuade your opponents from picking your creatures off. And let's not forget about Mathas' ability either, of course, though it may benefit some of your opponents you'll likely be the one who benefits the most from it. Path of Ancestry also lets you scry when you use its mana to cast a creature that shares a type with Sisay, of which there's a fair number, including Sisay herself. A similar advantage comes from Ashiok, Dream Render, who prevents our opponents from being able to search their decks, which is tremendously useful and lets us laugh as we take full advantage of our toolbox while they can't.
Removal/Board Wipes
Our primary board wipes are Urza's Ruinous Blast and In Garruk's Wake, both of which will take care of a great deal of threats with no or limited risk to our own board. Cyclonic Rift is of course as powerful as ever, though your opponents will possibly be able to replay things. Even so, it's an excellent way to slow them down while giving ourselves an opening to do something big. In terms of single-removal, Path to Exile and Swords to Plowshares are easy includes given their cost. Sure one gives an opponent an extra basic land and the other gives them a bit more life, but these can be small prices to pay to eliminate a nasty threat. Elspeth, Sun's Champion and Liliana, Dreadhorde General have some minus abilities that can remove some creatures your opponents have, though you'll risk losing stuff of your own so plan carefully. While not conventional removal, Ashiok, Dream Render can mill an opponent for four cards, but more importantly once that's done Ashiok then exiles all your opponents' graveyards, which is vital graveyard hate that can be useful against certain matchups.
Offensive Utility/Winning the Game!
Once we have our manabase set up and enough of a boardstate to start going on the offensive, one of our main goals should be to get Sisay out and bring out other legendaries to help buff her. The stronger Sisay is, the more and better things Sisay can search for. While not every 2-3 color combination is covered in this deck, there should be plenty of color combos among the legendaries to work with to help get all five colors between those other than Sisay. Of course, your opponents won't always make it easy to keep those legendaries or allow you to use Sisay's toolbox ability to its full potential, in which case you'll also be casting these legendaries normally as you draw them when searching for them isn't practical or possible. To aid with this, we have Kethis, the Hidden Hand, who will automatically reduce all legendary costs by one generic mana, as well as Rakdos, Lord of Riots, who will reduce creature costs depending on how much life you can take from your opponents in that turn. Rakdos is a bit trickier do manage, and you need to an opponent to lose life in order to cast him normally, however thanks to Sisay he can be cheated out from the deck fairly easily and having that extra bit of utility helps. Kethis also gives us some recursion for our legendaries as well, which can make all the difference. To further buff our commander,
Planeswalkers like Ajani, the Greathearted, Nissa, Voice of Zendikar, and The Royal Scions have great abilities that can make her and other creatures stronger. Hadana's Climb
will also give a boost at the start of each combat until it transforms. If you can get out Blind Obedience and Vela the Night-Clad, both should make it tougher for your opponents to have things out to block your creatures for combat, meaning if you can protect Sisay enough then taking someone out via commander damage could become a very real possibility. As well as going tall, we can also go wide with token generation from Kalitas, Traitor of Ghet. Nissa, Elspeth, and Liliana. Beyond that, if you can hold out long enough to use them, a great number of 'walker ultimates could spell the end for an opponent, Most notably those of Liliana, Nicol Bolas, the Arisen, and while it's the minus-three ability and not his ultimate that's the real killer, Sorin Markov.
