Thrummingbird

Flying
Whenever this creature deals combat damage to a player, proliferate. (Choose any number of permanents and/or players, then give each another counter of each kind already there.)

Celeborn the Wise

Whenever you attack with one or more Elves, scry 1.
Whenever you scry, Celeborn gets +1/+1 until end of turn for each card looked at while scrying this way.

Counterspell

Faerie Seer

Flying
When this creature enters, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Hardened Scales

If one or more +1/+1 counters would be put on a creature you control, that many plus one +1/+1 counters are put on it instead.

Island

Fated Infatuation

Create a token that's a copy of target creature you control. If it's your turn, scry 2.

Arwen Undómiel

Whenever you scry, put a +1/+1 counter on target creature.
{4}{G}{U}: Scry 2.

Galadriel of Lothlórien

Whenever the Ring tempts you, if you chose a creature other than Galadriel as your Ring-bearer, scry 3.
Whenever you scry, you may reveal the top card of your library. If a land card is revealed this way, put it onto the battlefield tapped.

Elvish Mariner

Whenever this creature attacks, scry 1.
Whenever you scry, tap up to X target nonland permanents, where X is the number of cards looked at while scrying this way.

Forest

Aragorn, the Uniter

Whenever you cast a white spell, create a 1/1 white Human Soldier creature token.
Whenever you cast a blue spell, scry 2.
Whenever you cast a red spell, Aragorn deals 3 damage to target opponent.
Whenever you cast a green spell, target creature gets +4/+4 until end of turn.

Fall of Gil-galad

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Scry 2.
II — Put two +1/+1 counters on target creature you control.
III — Until end of turn, target creature you control gains "When this creature dies, draw two cards." Then that creature fights up to one other target creature.

Elrond, Master of Healing

Whenever you scry, put a +1/+1 counter on each of up to X target creatures, where X is the number of cards looked at while scrying this way.
Whenever a creature you control with a +1/+1 counter on it becomes the target of a spell or ability an opponent controls, you may draw a card.

Elven Farsight

Scry 3, then you may reveal the top card of your library. If it's a creature card, draw a card.