Each new set provides an opportunity to update your Commander arsenal, and Zendikar Rising delivered a brand new mechanic: modal double-faced cards. If you haven't caught up with the recent set, no worries! I'll be your tour guide to Zendikar's latest mechanic and the best offerings for Commander players.
MDFC's are not too unlike transformed double-faced cards. Introduced back in Innistrad with the likes of Delver of Secrets, Bloodline Keeper and Reckless Waif (a 3/2 on turn 2, come on!), who were played out as side A and had the ability—whether triggered or activated—to flip over to side B, we now have a choice in the matter. When in hand, these new double-faced cards allow the player to cast or play side A or B. Each MDFC from Zendikar Rising is either a creature, sorcery, instant or land on one side with a land option on the reverse. Outside of the "dual land" options, each other MDFC:
This means cards that search for a "land" (e.g. Crop Rotation or Sylvan Scrying) cannot retrieve Valakut Awakening from your library.
Now that we're all caught up on the new mechanic, let's take a look at the cream of the crop; the creme de la creme; the modal double-faced cards you should consider picking up from Zendikar Rising (in no particular order).
Look up in the sky! It's a rare, it's a land! It's a pseudo-wheel that can draw you back up to hand size at instant speed for three mana.
This card is particularly good in Godo, Bandit Warlord, who's most interested in tutoring up Helm of the Host. Well, if that's in your hand, the dream isn't quite over: should Valakut Awakening also be in hand, you can put that Helm right back in the deck and dig for some rituals and protection to go along with that Godo cast. However, not only Godo will want this. Most any red list in need of card quality manipulators will want this. Unlike blue decks, which get to "scry till they die," red decks often lack the ability to work through their list to find cards in a dire moment. This is the answer red has needed, and at two generic and one red, it will be easy to splash as well.
I'm not going to say Hagra Mauling is for every list... but it could easily slot into most all lists.
At face value, it's a more expensive Murder. In Commander, it's likely to hit that 3-converted-mana-cost mark more often than not. Remember, only "an opponent" needs to have no basics, not the opponent whose creature you are targeting.
The question you're now asking yourself is: "Does Pat run Murder in Commander?" To which my reply would be a solid "No." However, do I run Swamps in my black Commander lists? Yeah, I definitely do. What's game changing about MDFC's is that the face value comes along with the benefit of hitting a land drop on turn. Folks often don't run enough removal in Commander. Hagra Mauling is that and a land for your deck. While I wouldn't recommend removing a Swamp for this, I would recommend adding this should your list lack single-target removal.
The cycle of mythic rare MDFC's are a bit special. Unlike their uncommon and rare brethren that are forced to come into play tapped, these have the choice to come into play tapped or untapped for a mere 3 life. Otherwise known as "bolt lands," these five cards are almost auto-includes within their given colors. If your life total can suffer 3 damage, you have a relevant land alongside a powerful effect.
Among the five, Turntimber Symbiosis is my personal favorite as it operates as an outlet within Selvala, Heart of the Wilds. Once you've demonstrated a combo for infinite mana, let's say with Cloudstone Curio + Wirewood Symbiote + Llanowar Elves and a creature with 6 power on the battlefield (why not the new Relic Golem?), you get to do something crazy:
You have a means to now play every creature from your list. With Genesis Hydra, you're able to bounce and recast it for an effect to enable haste, then go ahead and swing. All because you made the smart decision to play a land.
Does your list run some menacing creatures? How about creatures that provide value: card draw, ramp or a tax on noncreature spells? Phantasmal Image is the popular "clone" card, allowing you to copy a previously played Dockside Extortionist to generate gobs of mana. What if one of the lands in your list gave you that same opportunity?
For 3 CMC, you have a less frail Shapeshifter raring to add a ton of value to your boardstate. I do not believe you should replace lands from your list with MDFC's (outside of the Bolt Lands), but if your deck can use another clone effect, this is a must-own. The versatility of every MDFC is what makes them so appealing. Glasspool Mimic is special because the effect and her cost are not too far off from the immediately playable alternative. The fact she doubles as a land makes the package that much sweeter.
How about this for a value proposition: what if for that Stax list, with all those hatebears, you could play a land that also gave you the ability to recover those very creatures from the graveyard to your battlefield?
If you've just suffered a devastating board wipe, have had numerous creatures picked off from targeted removal or made some bad exchanges in combat, it's okay! Agadeem's Awakening is able to bring back all those creatures you so smartly played on curve and give you the board state you had a few turns prior, as if nothing ever happened. If your deck relies heavily on its creatures, this card is a slam dunk. At X=2, go ahead and grab that Collector Ouphe and Deathrite Shaman. Is that an Ornithopter in your grave? Yeah, grab that too.
Modal double-faced cards are easily the best mechanic to be introduced in a long time. Zendikar Rising is the sleeper set this year: I did not expect to see so much value from it, especially after following Double Masters. I hope MDFC's become evergreen, as the deck landscape will drastically change moving forward should we keep receiving more effects attached to lands.