Rhys the Exiled

Whenever Rhys the Exiled attacks, you gain 1 life for each Elf you control.
{B}, Sacrifice an Elf: Regenerate Rhys the Exiled.

Krosan Grip

Split second (As long as this spell is on the stack, players can't cast spells or activate abilities that aren't mana abilities.)
Destroy target artifact or enchantment.

Return Upon the Tide

Return target creature card from your graveyard to the battlefield. If it's an Elf, create two 1/1 green Elf Warrior creature tokens.
Foretell {3}{B} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Elven Cache

Return target card from your graveyard to your hand.

Joraga Treespeaker

Level up {1}{G} ({1}{G}: Put a level counter on this. Level up only as a sorcery.)
LEVEL 1-4
1/2
{T}: Add {G}{G}.
LEVEL 5+
1/4
Elves you control have "{T}: Add {G}{G}."

Lys Alana Bowmaster

Reach
Whenever you cast an Elf spell, you may have Lys Alana Bowmaster deal 2 damage to target creature with flying.

Shaman of the Pack

When Shaman of the Pack enters, target opponent loses life equal to the number of Elves you control.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control.)
Equip {1}

Marwyn, the Nurturer

Whenever another Elf you control enters, put a +1/+1 counter on Marwyn, the Nurturer.
{T}: Add an amount of {G} equal to Marwyn's power.

Poison-Tip Archer

Reach (This creature can block creatures with flying.)
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)
Whenever another creature dies, each opponent loses 1 life.

Jaheira, Friend of the Forest

Tokens you control have "{T}: Add {G}."
Choose a Background (You can have a Background as a second commander.)

Wrap in Vigor

Tyvar Kell

Elves you control have "{T}: Add {B}."
+1: Put a +1/+1 counter on up to one target Elf. Untap it. It gains deathtouch until end of turn.
0: Create a 1/1 green Elf Warrior creature token.
−6: You get an emblem with "Whenever you cast an Elf spell, it gains haste until end of turn and you draw two cards."

Harald Unites the Elves

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Mill three cards. You may put an Elf or Tyvar card from your graveyard onto the battlefield.
II — Put a +1/+1 counter on each Elf you control.
III — Whenever an Elf you control attacks this turn, target creature an opponent controls gets -1/-1 until end of turn.

Stoneforge Masterwork

Equipped creature gets +1/+1 for each other creature you control that shares a creature type with it.
Equip {2}

Freyalise, Llanowar's Fury

+2: Create a 1/1 green Elf Druid creature token with "{T}: Add {G}."
−2: Destroy target artifact or enchantment.
−6: Draw a card for each green creature you control.
Freyalise, Llanowar's Fury can be your commander.

Magewright's Stone

{1}, {T}: Untap target creature that has an activated ability with {T} in its cost.

Nullmage Shepherd

Tap four untapped creatures you control: Destroy target artifact or enchantment.

Wirewood Channeler

{T}: Add X mana of any one color, where X is the number of Elves on the battlefield.

Wolverine Riders

At the beginning of each upkeep, create a 1/1 green Elf Warrior creature token.
Whenever another Elf you control enters, you gain life equal to its toughness.

Lys Alana Huntmaster

Whenever you cast an Elf spell, you may create a 1/1 green Elf Warrior creature token.

Dwynen, Gilt-Leaf Daen

Reach
Other Elf creatures you control get +1/+1.
Whenever Dwynen, Gilt-Leaf Daen attacks, you gain 1 life for each attacking Elf you control.

Sword of the Animist

Equipped creature gets +1/+1.
Whenever equipped creature attacks, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.
Equip {2}

Elvish Eulogist

Sacrifice Elvish Eulogist: You gain 1 life for each Elf card in your graveyard.

Elvish Champion

Other Elf creatures get +1/+1 and have forestwalk. (They can't be blocked as long as defending player controls a Forest.)

Imperious Perfect

Other Elves you control get +1/+1.
{G}, {T}: Create a 1/1 green Elf Warrior creature token.

Putrefy

Destroy target artifact or creature. It can't be regenerated.

Nissa Revane

+1: Search your library for a card named Nissa's Chosen, put it onto the battlefield, then shuffle.
+1: You gain 2 life for each Elf you control.
−7: Search your library for any number of Elf creature cards, put them onto the battlefield, then shuffle.

Elvish Harbinger

When Elvish Harbinger enters, you may search your library for an Elf card, reveal it, then shuffle and put that card on top.
{T}: Add one mana of any color.

Crown of Skemfar

Enchant creature
Enchanted creature gets +1/+1 for each Elf you control and has reach.
{2}{G}: Return Crown of Skemfar from your graveyard to your hand.

Abomination of Llanowar

Vigilance; menace (This creature can't be blocked except by two or more creatures.)
Abomination of Llanowar's power and toughness are each equal to the number of Elves you control plus the number of Elf cards in your graveyard.

Wellwisher

{T}: You gain 1 life for each Elf on the battlefield.

Lys Alana Scarblade

{T}, Discard an Elf card: Target creature gets -X/-X until end of turn, where X is the number of Elves you control.

Sylvan Anthem

Green creatures you control get +1/+1.
Whenever a green creature you control enters, scry 1.

Reclamation Sage

When Reclamation Sage enters, you may destroy target artifact or enchantment.

Elven Ambush

Create a 1/1 green Elf Warrior creature token for each Elf you control.

Illusionist's Bracers

Whenever an ability of equipped creature is activated, if it isn't a mana ability, copy that ability. You may choose new targets for the copy.
Equip {3}

Wirewood Lodge

{T}: Add {C}.
{G}, {T}: Untap target Elf.

Wirewood Symbiote

Return an Elf you control to its owner's hand: Untap target creature. Activate only once each turn.

Priest of Titania

{T}: Add {G} for each Elf on the battlefield.

Wirewood Herald

When Wirewood Herald dies, you may search your library for an Elf card, reveal that card, put it into your hand, then shuffle.

Llanowar Tribe

Second Harvest

For each token you control, create a token that's a copy of that permanent.

Ambush Commander

Forests you control are 1/1 green Elf creatures that are still lands.
{1}{G}, Sacrifice an Elf: Target creature gets +3/+3 until end of turn.

Elvish Archdruid

Other Elf creatures you control get +1/+1.
{T}: Add {G} for each Elf you control.

Quirion Ranger

Return a Forest you control to its owner's hand: Untap target creature. Activate only once each turn.

Quirion Beastcaller

Whenever you cast a creature spell, put a +1/+1 counter on Quirion Beastcaller.
When Quirion Beastcaller dies, distribute X +1/+1 counters among any number of target creatures you control, where X is the number of +1/+1 counters on Quirion Beastcaller.

Elderfang Venom

Attacking Elves you control have deathtouch.
Whenever an Elf you control dies, each opponent loses 1 life and you gain 1 life.

Llanowar Elves

Fyndhorn Elves

Copperhorn Scout

Whenever Copperhorn Scout attacks, untap each other creature you control.

Lathril, Blade of the Elves

Menace
Whenever Lathril, Blade of the Elves deals combat damage to a player, create that many 1/1 green Elf Warrior creature tokens.
{T}, Tap ten untapped Elves you control: Each opponent loses 10 life and you gain 10 life.

Elvish Warmaster

Whenever one or more other Elves you control enter, create a 1/1 green Elf Warrior creature token. This ability triggers only once each turn.
{5}{G}{G}: Elves you control get +2/+2 and gain deathtouch until end of turn.