Don't Have

Heroes' Podium

Each legendary creature you control gets +1/+1 for each other legendary creature you control.
{X}, {T}: Look at the top X cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Mountain

Targ Nar, Demon-Fang Gnoll

Pack tactics — Whenever Targ Nar, Demon-Fang Gnoll attacks, if you attacked with creatures with total power 6 or greater this combat, attacking creatures get +1/+0 until end of turn.
{2}{R}{G}: Double Targ Nar's power and toughness until end of turn.

Tuya Bearclaw

Whenever Tuya Bearclaw attacks, it gets +X/+X until end of turn, where X is the greatest power among other creatures you control.

Rockfall Vale

Rockfall Vale enters tapped unless you control two or more other lands.
{T}: Add {R} or {G}.

Mirror Box

The "legend rule" doesn't apply to permanents you control.
Each legendary creature you control gets +1/+1.
Each nontoken creature you control gets +1/+1 for each other creature you control with the same name as that creature.

Zurgo Bellstriker

Zurgo Bellstriker can't block creatures with power 2 or greater.
Dash {1}{R} (You may cast this spell for its dash cost. If you do, it gains haste, and it's returned from the battlefield to its owner's hand at the beginning of the next end step.)

Reki, the History of Kamigawa

Whenever you cast a legendary spell, draw a card.

Ruric Thar, the Unbowed

Vigilance, reach
Ruric Thar, the Unbowed attacks each combat if able.
Whenever a player casts a noncreature spell, Ruric Thar deals 6 damage to that player.

The Ringhart Crest

As The Ringhart Crest enters, choose a creature type.
{T}: Add {G}. Spend this mana only to cast a creature spell of the chosen type or a legendary creature spell.

Kolvori, God of Kinship

As long as you control three or more legendary creatures, Kolvori gets +4/+2 and has vigilance.
{1}{G}, {T}: Look at the top six cards of your library. You may reveal a legendary creature card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

Kolvori, God of Kinship // The Ringhart Crest

Have

Minsc & Boo, Timeless Heroes

When Minsc & Boo, Timeless Heroes enters and at the beginning of your upkeep, you may create Boo, a legendary 1/1 red Hamster creature token with trample and haste.
+1: Put three +1/+1 counters on up to one target creature with trample or haste.
−2: Sacrifice a creature. When you do, Minsc & Boo, Timeless Heroes deals X damage to any target, where X is that creature's power. If the sacrificed creature was a Hamster, draw X cards.
Minsc & Boo, Timeless Heroes can be your commander.

Grand Warlord Radha

Haste
Whenever one or more creatures you control attack, add that much mana in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

Bard Class

(Gain the next level as a sorcery to add its ability.)
Legendary creatures you control enter with an additional +1/+1 counter on them.
{R}{G}: Level 2
Legendary spells you cast cost {R}{G} less to cast. This effect reduces only the amount of colored mana you pay.
{3}{R}{G}: Level 3
Whenever you cast a legendary spell, exile the top two cards of your library. You may play them this turn.

Traxos, Scourge of Kroog

Trample
Traxos, Scourge of Kroog enters tapped and doesn't untap during your untap step.
Whenever you cast a historic spell, untap Traxos. (Artifacts, legendaries, and Sagas are historic.)

Radha, Heir to Keld

Whenever Radha, Heir to Keld attacks, you may add {R}{R}.
{T}: Add {G}.

The Prismatic Bridge

At the beginning of your upkeep, reveal cards from the top of your library until you reveal a creature or planeswalker card. Put that card onto the battlefield and the rest on the bottom of your library in a random order.

Esika, God of the Tree

Vigilance
{T}: Add one mana of any color.
Other legendary creatures you control have vigilance and "{T}: Add one mana of any color."

Esika, God of the Tree // The Prismatic Bridge

Forest

Saryth, the Viper's Fang

Other tapped creatures you control have deathtouch.
Other untapped creatures you control have hexproof.
{1}, {T}: Untap another target creature or land you control.