Champions of the Perfect

As an additional cost to cast this spell, behold an Elf and exile it. (Exile an Elf you control or an Elf card from your hand.)
Whenever you cast a creature spell, draw a card.
When this creature leaves the battlefield, return the exiled card to its owner's hand.

Wirewood Channeler

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

Priest of Titania

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

Command Tower

{T}: Add one mana of any color in your commander's color identity.

Elvish Promenade

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

Arcane Signet

Marwyn, the Nurturer

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

High Perfect Morcant

Whenever High Perfect Morcant or another Elf you control enters, each opponent blights 1. (They each put a -1/-1 counter on a creature they control.)
Tap three untapped Elves you control: Proliferate. Activate only as a sorcery. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Talisman of Resilience

{T}: Add {C}.
{T}: Add {B} or {G}. This artifact deals 1 damage to you.

Llanowar Elves

Forest

Elvish Archdruid

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

Fyndhorn Elves

Golgari Signet

Lys Alana Huntmaster

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

Imperious Perfect

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

Swamp

Elves of Deep Shadow

{T}: Add {B}. This creature deals 1 damage to you.

Leaf-Crowned Visionary

Other Elves you control get +1/+1.
Whenever you cast an Elf spell, you may pay {G}. If you do, draw a card.

Realmwalker

Changeling (This card is every creature type.)
As this creature enters, choose a creature type.
You may look at the top card of your library any time.
You may cast creature spells of the chosen type from the top of your library.