I initially teetered on what commander deck I should build from Ikoria and C20, and after Yannik and Nikara came out in the Abzan pre-con, I knew that I had found an AWESOME commander pairing to build around. Most of the partner commanders in the pre-cons had something to do with counters, but I figured that because this sort of has a blink theme with Yannik and value from Nikara, I would give that a try!
The point of the deck is fairly simple, I want to get out ramp spells like Farhaven Elf or Fertilid so I can ramp into some serious cards that give me tons of value to control the board and get me ahead. Plus, with all my blink spells I can use these cards to get more value than a regular ramp spell (although I do have some of those in here too). Then, with those big cards, I can do some damage with cards like Siege Rhino or Gary or fetch out my combo pieces to close out the game as soon as possible. Things like Felidar Guardian, Panharmonicon, and Rune-Scarred Demon are all great cards that work together to allow me to get whatever card I want multiple times over. I also have Managorger Hydra and Champion of Lambholt so that if I decide I need to get my commander big enough for lethal damage, I can tuck it under Yannik or give Nikara counters to take out an opponent with no problem. I also have The Great Henge, Juniper Order Ranger, Renata, and Good-Fortune Unicorn so that even my smaller guys can get a bit bigger when I blink them, which can be useful if I face an opponent with a bigger board state than me. So, I have a 'go big and a little wide' strategy set up.
On top of that, I have cards like Conjurer's Closet, Otherworldly Journey, and Cloudshift so I can blink creatures like Wood Elves to get lands into play and use them on the same turn! I also have effects like Essense Warden and Corpse Knight, so that when I blink all my creatures I can gain some life while my opponents lose life! Plus, when I blink creatures with counters while I have Nikara out I can draw some cards off of it, which is always a plus! Hopefully, my value will get to the point where I have no much life that I won't need to worry about Nikara's damage.
While I may be running cards like Abrupt Decay and Anguished Unmaking to get rid of anything on my opponents' board, I also have Ravenous Chupacabra so that when I play or blink it, especially with Panharmonicon, I can clear out their boards to that I don't have to worry about any sort of crackback, which is a nice thing to not have to bother my (hopefully) cushioned life-total. I also have Eerie Interlude and Ghostway, so that if anyone tries to mess with my board or combo pieces I can negate it with no problem as well as giving me some value from my creatures re-entering the battlefield. For even more protection, I have Heroic Intervention and Lapse of Certainty so that if my opponents have some single-target removal I can give my wincons some much-needed protection. Also, just in case I'm playing against some blue decks, I have Destiny Spinner and Grand Abolisher so that I can make sure my permanents can enter the battlefield without having to worry about counterspells or things of the like.
Also, just in case any of my big creatures get put into my graveyard, I can always fish it out with Graveshifter or Phyrexian Delver. This way I don't have to worry about having one of my big-hitting cards being put into my graveyard. I can't stress how big a player Panharmonicon is in this deck. With it, I can be getting multiple cards back onto the battlefield at almost no cost to me while my opponents' are stuck trying to deal with all my shenanigans. I also have The Great Henge so that I'm getting card advantage from all of my creatures entering the battlefield, and with Nikara I can draw multiple cards every turn with just these two cards. I chose Henge over things like Guardian Project because Henge gives me the option to put a counter on my creatures, which really synergizes well with my deck. However, because I have cards like Henge as well as Junpier Order Ranger, Renata, and Good-Fortune Unicorn, I get even more card draw from Nikara, but it also runs the risk of forcing me to draw my own deck or damaging me out if I use my combos (which I'll bring up later). But the solution is to either assemble the combos early so I don't play these cards, or I ignore the combo and get TONS of value from these cards, so there is a plan in place to still win despite some hinderances. Another option is to just not have Nikara out when I combo, although that does put my value train back a bit with her not on the battlefield. Because of this, the combo is more of a last-ditch effort if I really need to win the game, so more often than not I will be using my counter-giving creatures to win a game in a more mid-level game. Armorcraft Judge also gives me good card-draw, since I'll have a good amount of creatues with counters on them, and with all of the blinking I'll be doing it will give me some serious value. On top of that I have lots of tutors, like Demonic Tutor, that can fish me out any card I want, and Worldly Tutor, that can get me some of my vital creatures or combo pieces. I also have Rune-Scarred Demon so that I can tutor multiple cards with just a simple flicker/blink effect.
Overall, the deck has quite a few powerhouse combos (that aren't infinite). With most of my cards and Conjurer's Closet, I can do basically everything I want the deck to be doing. I can have cards like Renata out on the battlefield that puts counters on everything, so this way I will always be drawing cards at my end step because of the flicker because of Nikara. Or with cards like Thragtusk, I can gain TONS of life as well as make enough beast tokens to swarm the board and attack or deter my opponents from attacking me. The one issue is that all of these cards are big targets, especially Conjurer's Closet. So, I made sure to run enough removal and to allow my creatures to stay on the battlefield for long enough to be worth while for me. Since most of my protection is flicker based, the issue is that I will lose counters on my big creatures like Managorger Hydra or Champion of Lambholt, but hopefully with everything I will be doing that won't be too big of an issue. Even though I am running lots of spot removal, I am running board wipes as well so I can get around pesky cards that have protection or hexproof or something-or-other. But, again, that isn't an issue for me with all my protection, so I can blink my guys or use Heroic Intervention to save my board so I can keep all my value pieces alive.
Since Yannik and Nikara can BOTH revolve around ETB triggers (and counters), I have a good amount of blinking abilities in my arsenal. I have cards like Felidar Guardian and Conjurer's Closet so that if I need the creature exiled with Yannik, I can get it when I need it and put another card under him, giving my Managorger Hydra or one of my commanders a ton of counters to swing for lethal, or at least some serious damage. My commanders make a great duo in themselves too. With Yannik I can put counters of any creatures I want that I control, and if I decide to blink Yannik and exile that card with counters, I can always draw a card off of it. Also, if my opponents try to take away my big guy, I can either draw a card when it dies or exile them under Yannik for more counters to negate the spell! (this only works if I can blink Yannik, so I need to make sure I have a spell like Cloudshift ready just in case)
Lastly, I'm running two infinite combos in this deck. The first one consists of Leonin Relic-Warder + Oblivion Ring/Journey to Nowhere + Yannik to get infinite ETB triggers. For this combo, what you have to do is play O-Ring on something, then play LRW to exile that enchantment. Then, play Yannik on LRW which brings back O-ring, then use O-ring on Yannik and repeat the process. This gives me infinite ETBs as well as infinite counters on any creature I control. My second combo has me running Felidar Guardian + Restoration Angel for another infinite ETB trigger combo. With either of these plus a card like Champion of Lambholt or Corpse Knight on the battlefield, I can either make one big guy or completely take then out with pings from Corpse Knight. I also have the option to put a bunch of counters in Nikara for commander damage, because with her menace she is a bit harder to block. I also have Essence Warden so that when my infinite ETBs go off I can also gain infinite life to cushion my life total just incase the game is getting difficult. But having as much life as I want makes it hard to take me out, so hopefully my opponents will scoop if that happens.
Note on interaction with my mass blink spells: The way mass blinking works with Nikara out is that she sees all my creatures leaving the battlefield so I would end up losing a bunch of life and drawing a ton of cards, depending on my board state, but I ALSO get to order which creatures return to the battlefield. The way both of these work is they are put onto the stack, so I get to choose which order the creatures get to re-enter the battlefield. Because of this, if I have a card like Renata out, I can choose to bring her back first and put counters on all of my creatures, or I could bring back Corpse Knight first to have my opponents lose a ton of life. I just have to be careful of this because I could end up losing more like than I would normally want to with Nikara's ability.
