About the Commander
Evelyn, the Covetous is one of the newest Grixis Commanders that New Capenna has introduced. The vampire brings a very interesting set of abilities and a mana cost with a big difference: despite its mana value being 5 (something relatively high for more competitive decks), the mana combination is great and allows us to cast it in different ways :
This casting cost flexibility helps in those times when the right combination of lands didn't come, too. And speaking of flexibility, Evelyn, the Covetous abilities allow you to choose different themes for your deck, or abuse them all, adapting to the table as your opponents play.
Her Flash allows you to keep your mana open for possible interactions and play her at the last possible moment, generating great value. That, however, isn't what makes the difference with the vampire. Flash with her second ability is what makes her a true Grixis commander (or Maestros, if you prefer).
Imagine an opponent uses a tutor like: Worldly Tutor, Vampiric Tutor, Mystical Tutor or any other that places a card on top. Using Evelyn, you can cast her during the draw phase, exiling the fetched card and playing it later. Its a hate against those tutor and you still pick up - most likely - a good card.
Finally, her last ability lets you play cards exiled with collection counters, but beware: the text is written so that only cards exiled by abilities you control can be played by you. That is, if an opponent controls an Evelyn, the Covetous, and both you and they have exiled cards with counters, you can only play yours, and they can only play theirs.
It's also important to note that if you exile a card, and it doesn't have a collection counter, you can't play it with Evelyn, the Covetous.
About the Deck
The deck has a strong Control footprint, with several interactions like counterspells and removals. The idea here is to dig until you find one of the combos, or play for luck and see what the top of the opponents offers. You can often find pieces there that will become your finishers, so be on the lookout.
In this deck, one of the most important features are discards. They will be responsible for placing Worldgorger Dragon in your graveyard, opening the doors for the combo. Each card in the list has a reason for being there, and they must be very clear so that you can see all the plays they provide:
Unmarked Grave: If you want to put the dragon straight from the deck into the graveyard. Easiest and recommended way to start the combo.
Other resources you can use to discard Worldgorger Dragon (from your deck or hand):
The interaction with Worldgorger Dragon
In case you don't already know, Worldgorger Dragon is infamous for its ability and interactions with reanimation enchantments that abuse it to generate "endless" mana.
The combo works like this:
3. When the dragon comes into play, it will exile all of your permanents, including the enchantment. Without the enchantment in play, the dragon will be put into the graveyard again, returning all of your permanents back to play.
4. When your permanents return, they return untapped. Add as much mana as you can to your pool and, with your enchantment, target Worldgorger Dragon again.
5. Go back to step 3.
You can interrupt the combo at any time by selecting another creature other than Worldgorger Dragon. After that, just take advantage of your mana resources to do whatever you want.
Evelyn, the Covetous, however, fits in the middle of the combo in a way that generates an interaction that guarantees you victory, if no opponent can prevent it. Because she has Flash, you can cast Evelyn, the Covetous mid-combo once you have enough mana to do so.
The idea here is to repeat this Worldgorger Dragon interaction to exile and return Evelyn, the Covetous each iteration, causing her ability to trigger, and you exile all cards from all players' library. Once that's done, just pass the turn and win.
Things get even more interesting if you use Necromancy as the combo initiator. As you can play it at instant speed, you can execute the combo any time you have priority, being able to combo on top of an opponent's combo, or enjoy a moment where everyone is unprepared.
Important point to note: This is a fragile combo. Worldgorger Dragon's abilities are split in two: One triggers when it enters the battlefield, exiling everything. Another triggers when he leaves the battlefield, giving everything back. If you somehow force his second ability to trigger before the first one resolves, you'll lose all your permanents forever.
Example: with the ability to exile everything on the stack, an opponent responds by exiling the dragon. The return all ability goes on the top stack and resolves, returning nothing (your permanents haven't been exiled, after all). The ability to exile all resolves then, and you lose all your permanents.
Because of this, be careful when you decide to start this combo to avoid being removed from the game (after all, it will be very difficult to resume your plans when you have no permanents in play).
Dualcaster Mage + Ghostly Flicker
Dualcaster Mage has been appearing on lists due to how easy it is to combo with him. Here it would be no different. The mage has great synergy with effects triggered upon entering the battlefield, and Evelyn, the Covetous is quite powerful. To abuse this effect, the card we will use to combo with Dualcaster Mage is Ghostly Flicker.
4. Evelyn, the Covetous will enter the battlefield and trigger her ability again.
6. Let Evelyn, the Covetous' trigger resolve.
7. Go back to step 3. Repeat until all players' libraries are exiled.
8. Pass the turn, and your opponents will lose the game.
Abusing Evelyn's Abilities
In this list, we have two ways to abuse Evelyn, the Covetous ability: manipulating the top to get value cards (yours and from your opponents) and triggering her ability multiple times, granting a wide range of possibilities.
Manipulating the top
The idea here is to always use one of these cards before you cast Evelyn, the Covetous, giving you an "extra" card or stealing a relevant card from your opponent.
Playing Scheming Symmetry can become almost like a Poker game: will your opponent fetch some kind of bomb, ignoring the fact that you can steal it with your Evelyn, the Covetous? Or will you fetch something useless to make sure you don't steal anything relevant? Depending on your reading of the situation, not playing Evelyn, the Covetous might be the best option, leaving the opponent to draw a dead card and delay himself.
These enchantments increase the fun factor exponentially. With Mirror March on play, each new creature you cast becomes a casino. How many copies will we be able to create? How many cards will we be able to exile? Depending on your luck, the game could end right there...
It is worth mentioning that the deck runs many creatures that generate value with its abilities, so multiple copies of Insolent Neonate or Ledger Shredder can make you dig deep into the deck and find just the combo piece you were missing.
Additionally, some of the most powerful combos in the current competitive Commander Metagame are part of her color identity:
Thassa's Oracle + Demonic Consultation
Underworld Breach + Lion's Eye Diamond + Brain Freeze
The list below is originally authored by Xingact, with minor changes.
Evelyn, the Covetous has proven to be an excellent choice for a Grixis commander due to the high flexibility she provides in both combo choices and mana combos.
Because she has a high toughness (4) and a powerful ETB effect, the vampire is not expected to die much during matches, so it's up to you to create the engines to abuse her ability through the combos mentioned here.
As a tribal commander, Evelyn, the Covetous certainly doesn't stand out much. The highest value she can offer is being on play, and when she's not, you'll always be left with the question: Do I play the vampires in my hand or wait to play when she enters the board? If you choose to play them without Evelyn, the Covetous, they will not bring the value expected by the deck. If you wait to cast it sooner, you run the risk of making the deck too slow.
In that sense, the ideal is a subtle combination, with a few vampires that generate value on their own and that their interaction with Evelyn, the Covetous is just an extra.