CREATURES
Arbor Elf, Boreal Druid, Elvish Mystic, Fyndhorn Elves, & Llanowar Elves- are the 1 cmc elf mana dorks that are the bread and butter of the deck, they are a great turn 1 start of any game, and help towards your elf count to go infinite.
Aven Mindcensor- is a great way to shut down you opponents' tutors, especially since it's a one sided effect.
Beast Whisperer- this deck is creature heavy, so this helps you draw a decent chunk of cards, and its counts towards your elf count.
Birds of Paradise- even though it's not a elf, Birds is still the best 1 cmc mana dork, and is an auto-include in any deck running .
Copperhorn Scout- works as a way to untap your huge army of mana dorks & Selvala to basically double your mana, it's incredibly efficient at only 1 mana and has the bonus of being an elf.
Elvish Archdruid, & Priest of Titania- are the two most important cards in the deck, they're the best elf mana dorks and are the two easiest way to get infinite mana in the deck (check the combo section for details).
Elvish Harbinger- tutors up one of the elf combo enablers, and taps for mana as another nice bonus, remember that the top of deck tutors are better in this deck than most, since you can draw it into your hand using Selvala's parley.
Elvish Reclaimer- is used to grab Gaea's Cradle and he goes towards your elf count.
Eternal Witness- is a solid way to recur any card from your graveyard.
Ezuri, Renegade Leader- used to protect your elves by regenerating your elves and is used as an infinite mana outlet.
Fauna Shaman- is an excellent repeatable tutor that also counts towards your elf count.
Grand Abolisher- is one of the best ways to keep your opponents from messing w/ you during your turn.
Heritage Druid- turns all your elves into mana dorks.
Marwyn, the Nurturer- can tap for a ton of mana, and can be an infinite mana generator if you can get her power to be at least 4.
Mirror Entity- is an elf and is an infinite mana outlet, plus it has a combo w/ Wirewood Symbiote (see combo section for details).
Oracle of Mul Daya- is normally a fantastic card for any deck, but it's real good in this deck since you can look at the top card for your library for Selvala parleys and you can play past your lands.
Quirion Ranger- is used to untap Selvala or another big mana generator, plus you can play the land to potentially net more mana, especially if you have anyway to play additional lands.
Recruiter of the Guard- searches up one of the key creatures for your combos or Stoneforge Mystic, so Stoneforge can find one of the infinite mana equipments.
Selvala, Heart of the Wilds- goes infinite w/ her and Umbral Mantle.
Stoneforge Mystic- is used to search up one of the infinite mana enablers equipment or Lightning Greaves if you need haste or protection for your creatures.
Sun Titan- used to recur your mana dorks or a ton of other possible targets in the deck.
Walking Ballista- is used as an infinite mana outlet.
Wirewood Symbiote- is used as a way to untap Selvala and other big mana dorks, and combos w/ Mirror Entity (look in combo section).
Wood Elves- counts towards your elf count and searches up a forest, also has great synergy w/ Wirewood Symbiote.
SORCERIES
Finale of Devastation- this is one of the most powerful cards in the deck, it is a deck to battlefield tutor and an infinite mana outlet.
Genesis Wave- is another infinite mana outlet and just a generically solid card, especially since just getting a ton of mana is relatively easy for the elfball strategy.
Green Sun's Zenith- is used as a deck to battlefield tutor for only green creatures, it's also a way to get Dryad Arbor out for 1 mana or X = 0.
Open the Armory, & Steelshaper's Gift- searches up Sword of the Paruns or Umbral Mantle as a infinite mana enablers or Lightning Greaves.
Wrath of God- is the only board wipe in the deck, since this deck is so creature heavy and board wipes aren't as powerful in C-EDH, however you do need at least one board wipe in the deck just in case of an emergency.
LANDS
Arid Mesa, Flooded Strand, Marsh Flats, Misty Rainforest, Verdant Catacombs, Windswept Heath, & Wooded Foothills- are all the fetch lands available in the color pairing.
Bountiful Promenade- is the Battlebond land for , which are fantastic lands that will almost always come into play untapped.
Brushland- the pain land for , pain lands are solid lands.
Cavern of Souls- this deck's creature base is mostly elves, so being able to protect them from countermagic is incredibly useful, especially for a competitive meta.
City of Brass & Mana Confluence- are auto-includes for any multicolored deck.
Command Tower- obliviously goes in every deck.
Dryad Arbor- in the deck so you can tutor it using Green Sun's Zenith.
4x Forest, & 2x Plains- are the number of basics used to fill in the rest of the mana base.
Gaea's Cradle- is one of the most powerful lands in commander, especially in a creature heavy deck like this.
Horizon Canopy- is an amazing land, especially in a Selesnya deck.
Reliquary Tower- this deck draws a lot of cards, so having no maximum hand size is incredibly valuable.
Savannah- an obvious inclusion for the land base.
Temple Garden- almost just as good as the ogrinal duals.
Wirewood Lodge- a perfect land for this deck, letting you net mana when untapping a big mana dork.
Wooded Bastion- the filter land for , filter lands are decent lands for 2-colored decks.
ARTIFACTS
Aetherflux Reservoir- you can gain a surprising amount of life using Selvala's ability, getting you to +50 life relatively easy. The deck can actually get a decent storm count w/ all the low drops in the deck and Selvala continually feeding your hand.
Chrome Mox, Mana Crypt, Mana Vault, Mox Diamond, & Sol Ring- are the typical fast mana that go into just about every competitive deck.
Lightning Greaves- gives haste to mana dorks so you can immediately tap them for mana plus shroud is a nice bonus.
Sensei's Divining Top- is already an incredibly efficient and powerful artifact, and it's even better in this deck since Selvala cares about the top of your library.
Staff of Domination- is an infinite mana outlet w/ some other decent abilities attached to it.
Sword of the Paruns, & Umbral Mantle- are purely used as a way to make infinite mana while being attached to a big mana dork that produces 4 or more mana.
Thousand-Year Elixir- is used so you can ignore summoning sickness for your mana dorks, and the untap ability is also a nice bonus to net some mana when untapping big mana dorks.
Winter Orb- the deck plays a ton of mana dorks and a decent chunk of mana rocks, so Winter Orb will usually hit opponents much harder than you.
INSTANTS
Angel's Grace- used to insure victory when comboing off.
Beast Within, & Generous Gift- are incredibly versatile removal spells that can hit any permanent at instant speed.
Chord of Calling- cheats a creature into play from your deck.
Crop Rotation- used to grab Gaea's Cradle.
Eladamri's Call- used to tutor up any creature to your hand.
Enlightened Tutor- can grab a myriad of useful enchantments and artifacts in the deck, including the combo enablers Umbral Mantle and Sword of the Paruns.
Force of Vigor- the green version of Force of Will, this deck draws a lot of cards, so exiling a card as the alternative casting cost should be an easy thing to achieve.
Heroic Intervention- this deck is incredibly dependent on creatures, so board wipes and even targeted removal can potentially take us out of the game, so protecting our creatures is incredibly important and Heroic Intervention is one of the best way to protect your permanents.
Nature's Claim- the most efficient artifact/enchantment removal spell in commander.
Path to Exile, & Swords to Plowshares- auto-includes in any deck running , including competitive decks.
Savage Summoning- used to get Walking Ballista into play without having to worry about counterspells, it can even be used at instant speed.
Seedtime- some anti- tech which is incredibly powerful.
Summoner's Pact- another great tutor for creatures.
Veil of Summer- protects against counterspells and targeted removal.
Worldly Tutor- tutors any creature on top of your deck.
ENCHANTMENTS
Aura Shards- the best way to continually destroy artifacts/enchantments, especially since this deck is creature heavy.
Blind Obedience- can significantly slow down your opponents' fast mana.
Carpet of Flowers- an incredibly powerful ramp spell, since is so heavily played in the competitive meta.
Concordant Crossroads- is used so, you don't have to worry about summoning sickness w/ your mana dorks.
Exploration- especially useful for this deck since it draws a lot of cards, so you can take advantage of the extra land drops.
Smothering Tithe- is already an auto-include in any deck, but it becomes absolutely ridiculous in Selvala, since parley triggers Smothering Tithe for each opponent.
Sylvan Library- an auto-include in any deck running , it's especially useful in this deck, since it somewhat allows you to stack the top of your deck.