Riku is my main homie, and has been since January 2013, when I needed to fill the new sleeves I got for Christmas four years ago. The deck has since been through 3 sets of sleeves and had most of the original cards replaced by stronger alternatives, but still follows the original creature toolbox strategy outlined by Sonik on MTGS in this excellent primer, which I later decided to reword and port over to DTR in my far shittier ripoff when Sonik's went dead. Well, DTR croaked a while ago as well, so now it's all your's, Tappedout.
RRRRRIKU
Commander breakdown
Riku of Two Reflections
Riku has a CMC of 5, no protection, and has almost no impact on the board when we play him. Seems bad, right? Well, it is, if we don't get the timing right. However, as Sonik points out, "[Riku is] an investment in your spells." We invest 5 mana and the better part of what we get to do for an entire turn in hopes of pulling off some crazy shit later. If we time him right and he lives until our next turn, the investment usually pays off. If he dies to removal, then we essentially wasted a turn and our next investment costs 2 more.
Riku is in my 3 favorite colors, two of which are arguably the best colors in multi-player EDH, while the third is generally considered the worst in the format, but does give us the Kiki-Conscripts combo and Sneak Attack.
Ability 1: Whenever you cast an instant or sorcery spell, you may pay . If you do, copy that spell. You may choose new targets for the copy.
Riku functions as a repeatable Fork, with the limitation that he can only copy our own spells. Some people see this and try to build a deck full of huge spells like Blatant Thievery. I'm going to tell you right now that this is a very stupid idea. The best use for this ability is usually to copy a ramp spell (4 CMC spells like Skyshroud Claim are great, since they fit our curve perfectly when copied), so that we have enough mana to copy something really big next turn. This ability is also great with extra turn spell, for obvious reasons. It doesn't really have any sort of synergy with counterspells, though, and as such, the deck is played tap-out style, and only plays cheap counterspells such as Glen Elendra Archmage and Swan Song that don't require holding up much mana, but are great for answering opponents' answers and protecting our own board.
Ability 2: Whenever another nontoken creature enters the battlefield under your control, you may pay . If you do, put a token that's a copy of that creature onto the battlefield.
For our deck, this is the better of the two abilities. As is true with instants and sorceries, you shouldn't just jam the most expensive things you can find into the deck and call it a day. Instead, Riku functions at his best when the deck is built with a well-defined curve, peaking at around 3-4 and dropping off significantly after 5. Additionally, we have very few creatures that are just beaters. Most are played solely for their strong ETB ability. Personally, I'd prefer that most of them were 1/1s, because then they'd cost less (Heartless Summoning would also be nice).
Notably, this ability works quite well with two all-stars pictured with Riku in the visual spoiler. With Riku and a Sneak Attack in play, we can pay for two ETB triggers and two hasty bodies, one of which sticks around after the turn ends. Similarly, when operating a Birthing Pod chain, we get the nifty bonus of getting to keep a copy of the creature we fetched last time. Generally speaking, Riku is really mana-hungry and the creatures most worth copying are also the most expensive, so cheating them into play for 1 is damn powerful.
The Creature Toolbox
Many people will call my deck a "goodstuff" deck. I'm not saying that they're wrong (it's not a "badstuff" deck ;) ), but there's much more to it than that. It is a toolbox deck--more specifically, a creature toolbox deck. It has many cards that can tutor for creatures (Birthing Pod, Worldly Tutor, Fauna Shaman, Green Sun's Zenith, and Eldritch Evolution, among others), along with tutors for our creature tutors (Fabricate, for Birthing Pod, along with Mystical Tutor, for Worldly Tutor or GSZ, and all of our instant and sorcery answers), that allow us to find the card that's perfect for the situation.
Do they have a troublesome noncreature permanent? Acidic Slime will take care of that.
Having problems with creatures? Look for Ixidron, Duplicant or Inferno Titan, or just play something bigger and wall it.
Need more mana in order to do something huge? That's why we have Oracle of Mul Daya, Wood Elves, Farhaven Elf, Sakura-Tribe Elder, and Trinket Mage.
Is the answer already in the graveyard? Get it back with Eternal Witness.
Deadeye Navigator (coupled with another fatty), Craterhoof Behemoth, Avenger of Zendikar, Tooth and Nail and Rite of Replication win us the game, and Spike Weaver and Glen Elendra Archmage protect us while we set up.
So, why do we build our toolbox out of creatures? After all, answers are typically much cheaper and more versatile when they aren't permanents, and we're not playing our creatures for their P/T. The answer is that green's creature tutors are stronger and more numerous than blue's instant and sorcery tutors. And while I do play Mystical Tutor and many instants and sorceries that can be viewed collectively as a toolbox, I have only explored a very small part of the potential to build a spell toolbox given my options. Why don't I explore it further? Well, I find that, with this deck (and toolbox decks in general), it is best when every one of our tutors is capable of finding the answer we need. It's why I'm playing Manglehorn over Krosan Grip. And even if I could run Vindicate, I wouldn't replace Acidic Slime with it even though it is a better card, because the inclusion of Acidic Slime makes all of my creature tutors more powerful (It would, however, straight up replace Beast Within.
Creatures also have a few other things going for them, even if they are small:
-They can block. Why is Sakura-Tribe Elder better than Rampant Growth? It does pretty much the same thing, and can prevent some damage as well.
-They are easier to recur from the graveyard. I'd like to note that this is definitely a double-edged sword in EDH (black reanimates our graveyard better than we do), and our deck has just as many ways of recurring used spells as dead creatures.
-They can feed Skullclamp.
-They can be exchanged for better creatures via Fauna Shaman, Survival of the Fittest, Eldritch Evolution, or Birthing Pod.
Birthing Pod
This brings me to my next point: Birthing Pod is the best card in the deck. It is 80% of the reason why Fabricate is in the deck. You don't even have to play the deck to see how powerful and important a repeatable tutor is for a toolbox deck. It becomes even more powerful when we fill our deck with creatures with powerful ETBs at every point in the curve. Since a large part of our rationale behind including each creature in the deck is its ETB trigger, we usually don't mind throwing our creatures into the Pod. I would also like to note that Riku can copy the creatures that Birthing Pod brings into play from our libraries. If only Riku could copy Birthing Pod...
Birthing Pod is also the engine behind the deck's most common means of victory. In an ideal game, we play a three drop into Riku, pass, untap, and play Birthing Pod and Pod the 3 drop into a 4 drop that we copy with Riku, and on the next turn, Pod one 4 drop into a Zealous Conscripts that untaps Birthing Pod, allowing us to Pod the other 4 drop into Kiki-Jiki, Mirror Breaker for infinite hasty 3/3s.
Oh, and I'd like to take a moment to thank Wizards for making Craterhoof Behemoth cost more than Avenger of Zendikar.
On Mana, Ramp, and Lands
Riku is mana-hungry. Incredibly so. And that's just the way we want him to be. According to the mana sum theory, the winner of a game of MTG tends to be the player who has spent the most mana. Keeping this in mind, we construct our deck so that we will have something to do with all of our mana until we win the game. We do this by being conscious of our mana curve when choosing cards for the deck, by including a number of spells that draw more cards, and, of course, by copying our spells and creatures with Riku.
Because of this, ramp is so damn important to the deck. In order to do big things, we need big mana. And to do these things a turn or two before the decks that don't find their early ramp (or don't even play much ramp at all :o ) is huge for us. This is the reason why green is one of the two best colors in the format, and why I run about a dozen ramp spells in this deck, along with tutors for those spells (yes, I will tutor for a ramp spell). Generally speaking, most of our best games involve a turn 4 Riku, so it's usually a good idea to mulligan hands that don't have any mana acceleration.
Ramp also serves as color fixing. If you're on a budget, you can get away with a mostly-basic land base if you run enough ramp spells and skew your mana base towards green so that you can hit those ramp spells early and have them find the rest of your colors for you. Land ramp is the best type of ramp, as land destruction is less common and more expensive than most other types of permanent destruction.
Combos and Other Kills
Infinite Creatures
Kiki-Jiki, Mirror Breaker + Zealous Conscripts
Kiki-Conscripts is the deck's foremost combo. Kiki-Jiki taps to create a copy of Zealous Conscripts, which, upon entry, triggers to gain control of, untap, and grant haste to a permanent of our choice. We'll choose Kiki-Jiki, Mirror Breaker every time (even though we already control it and it has Haste printed on the card) since untapping him allows us to repeat the process and make an arbitrarily large number of hasty Zealous Conscripts.
Birthing Pod + Glen Elendra Archmage
As mentioned in the visual spoiler, Glen Elendra Archmage is especially powerful because we can put this combo on board and kill in one turn with Archmage and and untapped Birthing Pod. Sacrifice Archmage to Pod to find Conscripts, untapping Pod, and then Pod the persisted Archmage into Kiki-Jiki.
Eldritch Evolution + Wood Elves / Farhaven Elf / Trinket Mage
Wood Elves, Farhaven Elf, and Trinket Mage (fetching Sol Ring) both enable turn 4 Riku and give us a 3CMC body to sacrifice to Eldritch Evolution, which we can cast and copy with Riku on turn 5 (even if we miss our fifth land drop) to find Kiki & Conscripts to end the game early.
Infinite Mana & Infinite (Flying) Creatures
Palinchron
Palinchron creates the most easily-assembled infinite combo in the deck. With Riku on the battlefield, Palinchron in hand, 7 mana in your mana pool and 7 tapped lands, we can create infinite red, blue and green mana (assuming we have at least 1 red-producing, 1 green-producing and 3 blue-producing lands) and infinite Palinchrons, finishing with the real Palinchron in hand to do it again if something happens that destroys the board and prevents us from winning. It's fairly straightforward, but I'll run through it anyway:
-Cast Palinchron. Put Riku's trigger on the stack, then Palinchron's.
-Untap 7 lands.
-Tap for 7 mana, pay to copy the Palinchron that just entered.
-Untap 7 lands.
-Pay to return the original Palinchron to our hand. We have 7 untapped lands and 1 mana floating. Tap 7 lands and return to the start of the loop, netting 1 (hopefully colored) mana each time.
There's not too much for the deck to do with infinite mana, and infinitely many creatures will usually just end the game once we untap (since infinite flying creatures also means infinitely many flying blockers to protect us until then), but it's worth noting that the Palinchron combo also allows for infinite Desolate Lighthouse activations, allowing us to dig for Lightning Greaves and Kessig Wolf Run (and Exploration, if we don't have a land drop left this turn) for a same-turn kill.
Infinite Turns
Time Warp +Eternal Witness + Crystal Shard
With 8 mana, we can use Crystal Shard to bounce our Eternal Witness, allowing us to replay it and return Time Warp to our hand, then cast Time Warp so we can do the same thing next turn until we've found enough attackers and lands to win the game.
Very-Many-But-Not-Infinite Turns
Even without a Crystal Shard, if we get to copy a Time Warp with Riku, we're still probably winning the game. Hopefully, we've recognized this line a little earlier and have a tutor saved up/allow ourselves to find a tutor within our two free turns to grab a Snapcaster Mage, Eternal Witness or Regrowth and replay the Time Warp for even more turns. People tend to quit before the third extra turn.
Avenger & Craterhoof
Avenger of Zendikar + Craterhoof Behemoth
The classic. Make lots of tokens, then cast Overrun three times. Although they're not the go-to Tooth and Nail targets for this deck (Kiki-Conscripts is just better), Avenger-Craterhoof has the upside of being mono green, so the pieces can be found with GSZ. Additionally, we can Pod Avenger into Craterhoof.
Craterhoof Alone
Craterhoof is strong even without 20 plant tokens. If we draw Sneak Attack, the plan is usually to get Craterhoof into our hand so we can cheat it in and copy it with Riku. With even a few other creatures in hand, we're looking at a good number of overruns on hasty bodies. If one of those creatures is a clone, the Craterhoof buffs really add up and we can one-shot the table, sometimes even pulling off 21 commander damage.
I'm still unsure on whether I should refer to Riku in singular or plural
