Have

Captain Sisay

{T}: Search your library for a legendary card, reveal that card, put it into your hand, then shuffle.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Elesh Norn, Grand Cenobite

Vigilance
Other creatures you control get +2/+2.
Creatures your opponents control get -2/-2.

Sting, the Glinting Dagger

Equipped creature gets +1/+1 and has haste.
At the beginning of each combat, untap equipped creature.
Equipped creature has first strike as long as it's blocking or blocked by a Goblin or Orc.
Equip {2}

Reki, the History of Kamigawa

Whenever you cast a legendary spell, draw a card.

Urza's Ruinous Blast

(You may cast a legendary sorcery only if you control a legendary creature or planeswalker.)
Exile all nonland permanents that aren't legendary.

Thousand-Year Elixir

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

Linvala, Keeper of Silence

Flying
Activated abilities of creatures your opponents control can't be activated.

Shalai, Voice of Plenty

Flying
You, planeswalkers you control, and other creatures you control have hexproof.
{4}{G}{G}: Put a +1/+1 counter on each creature you control.

Yasharn, Implacable Earth

When Yasharn enters, search your library for a basic Forest card and a basic Plains card, reveal those cards, put them into your hand, then shuffle.
Players can't pay life or sacrifice nonland permanents to cast spells or activate abilities.