Commander
Deck list
View Grixis Vampire tribal in Archidekt
About Evelyn the Covetous
Evelyn is a Grixis colored vampire tribal commander providing card advantage when a vampire enters the battlefield and possibly removes an opponents wincon at the same time.
Evelyn allows you to play a single card exiled with Evelyns ability once a turn, meaning timing restrictions apply and you need Evelyn on the battlefield when you are playing the card.
Evelyn, the Covetous in EDHREC
In EDHREC Evelyn the Covetous has under a thousand decks, 879. Evelyn is definitely not from the strongest side of the commanders, and the high CMC makes her difficult commander to brew around effectively.
I originally posted the deck with power level 5, but after a few very successful games, I'd argue Evelyn with this build is at least power level 6, and easily upgradeable to levels 7 or even 8. Reasoning behind this following: if you are able to ramp into 5 quickly, the Flash ability allows you to make reactions according to the situation as needed, and provides a quaranteed land drop on your every turn. And the higher your opponents power level (meaning the more interaction they have), the more solutions you will receive from otherwise useless 1/1 vampires.
Possible themes for Evelyn
Vampire tribal theme
Evelyn cares a lot of vampires ETBing on your side. With a heavy combat side, Evelyn works as a card advantage purely, and the decks would be combat focused Grixis vampire tribal decks. The decks would be resilient without the commander, and the commander would serve as an extra vampire most likely. This kind of build is not something I'm after.
Theft cast theme
Theft cast themed deck with Evelyn is packed with 1 and 2 cmc vampires, multiple hexproof/shroud providers and some protection spells for point removals for Evelyn. Theft deck aim to use opponents wincons, removals and draw spells and exiles the unusable wincons from the libraries.
Strategy
Early game and mulligans
As we are trying to exile opponents cards and to use them ourselves, we need lots of ramp. In Grixis colors ramping is mostly done with artifact ramping and this deck runs 16 mana rocks and 31 lands. The low land amount is balanced with Evelyns exile ability and the high amount of mana rocks. Evelyn allows to play a land too from exile.
Mulligans: We want Evelyn out as fast as possible, so a great starting hand has minimun o 2 lands and at least one mana rock. Also lookout for at least one vampire to play after casting Evelyn.
Best plays in Early game: Pongify, Knight of the Ebon Legion, Stromkirk Noble and any of the 2 cmc mana rocks.
Mid game
T4 to T6 are mid game and the focus is to get Evelyn on the battlefield. Evelyns flash ability is great to be used, and grixis colors provides a huge amount of instant speed removal so play the opponents and try to persuade them to attack your opponents instead.
When you get Evelyn on the battlefield, she will trigger the exiling from herself, too, so if you miss a land drop, it is a good idea to get one from the exile effect!
Great Mid game plays: Mana Echoes, Molten Echoes, Flameshadow Conjuring, Pawn of Ulamog and Wild-Magic Sorcerer.
Late game
T6+ are the late game and we should have multiple cards in the exile as our extension of the hand. Most likely the hand itself is quite low on resources, unless our opponents have provided us with some nice card draw!
Evelyn vampire tribal is a slower deck, so the big plays and game enders are in the late game. Main wincons are actually opponents wincons and absurd value creation from the exile effects.
Great late game bombs: Whatever good-stuff we have exiled from our opponents!
Winning the game
As a backup it somewhat difficult to win with opponents wincons, so the deck does have a few combat focused wincons: Anhelo the Painter allows to copy the first instant or sorcesr spellyou play by saccing a power 2 creature. Shared Animosity allows us to win with pure combat. Predator's Hour makes our creatures hard to block AND provides with a similar trigger as Evelyn when they connect to an opponent.
Who is the deck for
Evelyn vampire tribal is without a doubt a difficult deck to play as one never knows what resources are available from the opponents. Due to this most of the interaction and card draw in the deck are instants to increase the odds of having answers at hand whenever needed.
If your pod plays some nasty decks I'd argue Evelyn is a great choice to shove those same unpleasant cards against themselves as an argument.
I can't recommend Evelyn if you can't stand playing opponents cards (read you don't want your opponents to play your cards) or you want to win the games always as Evelyn is a weaker commander.