Jagged-Scar Archers

Jagged-Scar Archers's power and toughness are each equal to the number of Elves you control.
{T}: Jagged-Scar Archers deals damage equal to its power to target creature with flying.

Elvish Promenade

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

Swamp

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.

Imperious Perfect

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

Wirewood Pride

Target creature gets +X/+X until end of turn, where X is the number of Elves on the battlefield.

Elvish Archdruid

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

Forest

Aphetto Dredging

Return up to three target creature cards of the creature type of your choice from your graveyard to your hand.

Bramblewood Paragon

Each other Warrior creature you control enters with an additional +1/+1 counter on it.
Each creature you control with a +1/+1 counter on it has trample.

Wirewood Lodge

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

Timberwatch Elf

{T}: Target creature gets +X/+X until end of turn, where X is the number of Elves on the battlefield.

Taunting Elf

All creatures able to block Taunting Elf do so.

Lys Alana Huntmaster

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

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.

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.

Thousand-Year Elixir

You may activate abilities of creatures you control as though those creatures had haste.
{1}, {T}: Untap target creature.

Wellwisher

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

Heedless One

Trample
Heedless One's power and toughness are each equal to the number of Elves on the battlefield.

Priest of Titania

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

Immaculate Magistrate

{T}: Put a +1/+1 counter on target creature for each Elf you control.

Leaf Gilder

Wren's Run Vanquisher

As an additional cost to cast this spell, reveal an Elf card from your hand or pay {3}.
Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Vendetta

Destroy target nonblack creature. It can't be regenerated. You lose life equal to that creature's toughness.