Mox Amber

{T}: Add one mana of any color among legendary creatures and planeswalkers you control.

Merry, Esquire of Rohan

Haste
Merry, Esquire of Rohan has first strike as long as it's equipped.
Whenever you attack with Merry and another legendary creature, draw a card.

Arbaaz Mir

Whenever Arbaaz Mir or another nontoken historic permanent you control enters, Arbaaz Mir deals 1 damage to each opponent and you gain 1 life. (Artifacts, legendaries, and Sagas are historic.)

City of Brass

Whenever City of Brass becomes tapped, it deals 1 damage to you.
{T}: Add one mana of any color.

Plaza of Heroes

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell.
{T}: Add one mana of any color among legendary permanents you control.
{3}, {T}, Exile Plaza of Heroes: Target legendary creature gains hexproof and indestructible until end of turn.

Basim Ibn Ishaq

Whenever you cast a historic spell, draw a card. Basim Ibn Ishaq can't be blocked this turn. This ability triggers only once each turn. (Artifacts, legendaries, and Sagas are historic.)
Whenever Basim Ibn Ishaq deals combat damage to a player, put a +1/+1 counter on it.

Flowering of the White Tree

Legendary creatures you control get +2/+1 and have ward {1}.
Nonlegendary creatures you control get +1/+1.