"Protected by glamers and guile, Glen Elendra harbors the elusive Oona, queen of the fae."
Oona, Queen of the Fae is a massive flying General that can win in two very different ways with the same simple, powerful activated ability.
Oona has basically only two modes of play: beatdown with flying tokens, or milling with infinite mana. We will focus on milling since there are very few Commander decks that are really good at milling. This can be accomplished with a simple 'infinite-mana' combo.
I personally don't like combo decks, but they are an essential part of Magic: the Gathering, and sometimes you actually find a General that actually does something different and fun for a change (unlike the so-called jerk-commanders: Sharuum, Reaper King, Zur, etc.). Now, milling is usually dismissed because there are a lot of cards that automatically recover the whole deck when they hit the graveyard, but Oona is different. She EXILES every single card that she mills, so they never hit the graveyard. Those triggered effects won't do anything.
Now, you need a combination of cards that can produce a huge amount of mana with as few resources as possible. Here you have a list of three different two-card combinations that can produce 'infinite-mana':
Grand Architect + Pili-Pala
You will only need one Blue mana to get infinite colored mana here. This is by far the easiest way to produce infinite colored mana in this Commander deck. You will pay one Blue mana to make Pili-Pala Blue with Grand Architect's first activated ability. Then, you will tap the scarecrow with Grand Architect's SECOND activated ability to produce 2 colorless mana. Use this mana to untap Pili-Pala with its own activated ability to get one colored mana, then repeat the same steps a million times with Grand Architect. This will score one clean colored mana per each combo cycle, which translates into a lot of colored mana, when you decide to stop the combo loop.
In other words:
1) Grand Architect's 1st activated ability on Pili-Pala,
2) Grand Architect's 2nd activated ability on Pili-Pala,
3) Pili-Pala's activated ability,
Here is another way of producing infinite mana:
Basalt Monolith + Rings of Brighthearth
This combination is a little more costly (both permanents cost three mana); you will need two mana to activate Rings of Brighthearth's triggered ability. Also, the infinite mana that it generates is colorless, not colored, like the mana Pili-Pala produces. This means that you will need one extra Black or Blue mana per each opponent that you have since you need one Black or Blue mana to unleash Oona's activated ability.
This particular loops works in the following manner: You tap Basalt Monolith to get three colorless mana, but before resolving it, you also activate Rings of Brighthearth's triggered ability by paying two colorless mana. This will result in duplicating Basalt Monolith's effect, netting you six colorless mana. You will use three of those six colorless mana to activate Basalt Monolith's second activated ability, which untaps it. Then, you will tap Basalt Monolith again and use two of the remaining three mana to activate Rings of Brighthearth's triggered ability yet again, scoring you six more colorless mana. The difference here is that you still have one extra colorless mana from the last six mana you generated from the first loop. This means that you will use a total of five mana to recreate the combo loop, leaving you with one clean colorless mana per combo cycle. This translates into a lot of colorless mana, until you decide to stop the loop.
In other words:
1) Tap Basalt Monolith + activate Rings of Brighthearth = 6 mana
2) Pay 3 to untap Basalt Monolith.
And here is the third combination:
Doubling Cube + Filigree Sages
This is the most mana intensive combination of the three combos, but it still works pretty well. You need to have at least ten mana in your mana pool to unleash this loop. You will need ten or more mana because Doubling Cube's activated ability plus Filigree Sages' activated ability's activation cost only makes a positive difference when you have at least ten mana in your mana pool. Even with nine mana, you will just recover the lost nine mana at the end, making no difference whatsoever in your total mana count, and with eight mana you will just end up wasting your resources.
First, dump ten mana into your mana pool (make sure to at least have one Blue or Black mana; this will be used later to activate Oona's activated ability for each of your opponents, plus Filigree Sages' activated ability, which requires one Blue mana per activation). Then, after you have those ten mana floating around, use three of them to activate Doubling Cube, duplicating your remaining seven mana and scoring you a total of 14 mana. Use three of those 14 mana to activate Filigree Sages' activated ability and use it to untap Doubling Cube. By now, you will have eleven remaining mana. Use three to tap Doubling Cube and duplicate your now remaining eight mana and generate 16 new mana. Here you can see that there is a positive difference of at least 2 more mana from the first duplication. Call this process into a loop to produce a lot of colored and colorless mana, until you decide to stop the loop.
In other words:
1) Get 10 mana.
2) Double mana with Doubling Cube = 14 mana
3) Filigree Sages' activated ability on Doubling Cube = 11 mana
After you activate one of the above three combinations of cards to produce a lot of mana, simply dump all that many in as many triggers of Oona's activated ability as there are opponents in your table. As I said earlier, you will need at least one Black or Blue mana to activate Oona's activated ability, plus an amount of mana sufficient to completely mill each of your opponents libraries. Just call for X=100 or more mana on each activation, and you will mill everybody up.
You can also use Exsanguinate to eliminate everybody pretty easily, but you will need another extra tutor to search for this Black sorcery if you want to go the very easy way:
Just pay X=40, or more if you want, to kill everybody instantly.
Yet another spell that you can use to kill only one player is Blue Sun's Zenith:
You might want to use this instant to draw some cards for yourself, but if it somehow gets very difficult to get out Oona, you can always mill only one player with infinite mana and Blue Sun's Zenith!
There is another cheap, fantastic milling combo that is unrelated to Oona's ability, but shares her Commander Identity colors:
You just need to wait for an opponent to lose life. You can make it yourself of wait for an opponent to do it. Then, you pay three mana to activate Duskmantle Guildmage's first ability while Mindcrank is on your side of the battlefield. This automatically generates an infinite loop that entirely mills (or actually kills by life-draining) one of your opponents. Any player that loses life is subject to this fatal combo by just paying three mana. Also, if you manage to accumulate a lot of mana with one of the combos from before, you can also mill all of your opponent's libraries with Duskmantle Guildmage's second activated ability.
That's it. Thats how you combo and mill everybody with just two cards and your General, or bleed everybody out with just one sorcery.
Notice that Increasing Ambition can search for up to three cards! Try to focus on searching for the easiest combination available. Always go for Grand Architect and Pili-Pala, if possible.
After you fetch the combo pieces, you will need protection to cast them plus your General. This deck can use either counter magic or equipments that give some kind of protection to your General.
Hinder and Spell Crumple are always great against Generals. Erayo is so broken in Commander that it was banned as a General, but it can still be used in your 99 card count for the Commander deck. Ertai is another excellent recurrent source of countermagic, with a cost. Draining Whelk and Glen Elendra Archmage both give you extra value out of a single body. Voidmage Husher is a little special since you can use her to negate an activated ability, block with her, then bound her back by playing some kind of instant spell, giving you a LOT of utility out of a single uncommon. Spelljack and Desertion are fan-favorites because they give you a lot of value out of a single instant spell, which is something very rare.
There are other ways to protect your General. Here is also a small list of equipments that you can use to evade removal of Oona:
You will also need removal to deal with those creatures that manage to trespass your countermagic net.
I highlight All is Dust because it can wipe out the board from a lot of things, but without touching some of your combo pieces (since some of them are colorless artifacts)!
There are times when removal is not an option. There are a lot of effects and combos that trigger or activate when creatures die or when they recur from the graveyard. In those particular cases you can opt for massive bounce effects:
These big spells are emergency-only stuff, just like with most mass-removal spells. They will kill or bounce your own creatures too, so be wary about that.
Cyclonic Rift is THE bounce spell in Commander. It's overload ability is just insane and it is even better than Inundate in this deck. Venser, Shaper Savant is a little special because, although he cannot sweet everything or recur himself into your hand, he does deal with ANY kind of thing (including spells waiting to resolve in the stack) that you want to bounce. He can even bounce Generals into their owners hands!
Card-drawing is also important in any deck, and Blue has many ways to accomplish this!
This deck has a lot of wizards, including Oona herself, so you Azami, Lady of Scrolls feels at home in this milling brew. As it was mentioned before, Blue Sun's Zenith can be used to kill one player by milling if you manage to assemble one of the three mana-producing combos. It also works great as a card drawing spell for yourself.
Here are some recursive spells to recover certain lost cards that you may need back:
While Archaeomancer and Mnemonic Wall recover counters and other useful stuff, Beacon of Unrest can revive your precious combo pieces, if they get destroyed or sent to the graveyard. Note that Beacon of Unrest can also be used on your opponent's graveyard!
To get all this stuff going on, you need at least some mana ramp. Every Commander deck runs some sort of mana ramp. Black and Blue are not particularly great at that, but there is always a way to fix that department:
Leyline of the Void will shut down graveyard and recursion based strategies, while Leyline of Anticipation will let you cast your combo pieces at the least expected moment.
Utility lands are always welcome!
Buried Ruin enables the recovery of your precious artifacts; your combo pieces! Volrath's Stronghold makes the same, but for any kind of creature and without getting sacrificed! Bojuka Bog also eliminates graveyard based combos and mechanics.
Multi-colored lands are always needed in every Commander deck that uses two or more colors. Here is the full suite of dual lands for Black and Blue in Commander:
The remainder of the deck can be filled with an equal amount of Swamps and Islands.
Here is a list of this sample deck, for your reference:
-Oona, Queen of the Fae
-Glen Elendra Archmage
-Erayo, Soratami Ascendant
-Ertai, Wizard Adept
-Venser, Shaper Savant
-Azami, Lady of Scrolls
-Arcanis, the Omnipotent
-Rings of Brighthearth
- Sol Ring
-Tezzeret the Seeker
-Beseech the Queen
-Decree of Pain
-Dregs of Sorrow
-All is Dust
-Beacon of Unrest
-Blue Sun’s Zenith
-Leyline of Anticipation
-Leyline of the Void
-River of Tears
Grind every single thought!