Trailblazer's Torch

When Trailblazer's Torch enters, you take the initiative.
Whenever equipped creature becomes blocked, it deals 2 damage to each creature blocking it.
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Safana, Calimport Cutthroat

Menace
At the beginning of your end step, if you have the initiative, create a Treasure token. Create three of those tokens instead if you've completed a dungeon.
Choose a Background (You can have a Background as a second commander.)

Aarakocra Sneak

Flying
When Aarakocra Sneak enters, you take the initiative.

Vicious Battlerager

When Vicious Battlerager enters, you take the initiative.
Spiked Retribution — Whenever Vicious Battlerager becomes blocked by a creature, that creature's controller loses 5 life.

Underdark Explorer

Menace (This creature can't be blocked except by two or more creatures.)
When Underdark Explorer enters, you take the initiative.

Passageway Seer

Lifelink
When Passageway Seer enters, you take the initiative.
At the beginning of your end step, if you have the initiative, put a +1/+1 counter on Passageway Seer.

From the Catacombs

Put target creature card from a graveyard onto the battlefield under your control with a corpse counter on it. You take the initiative. If that creature would leave the battlefield, exile it instead of putting it anywhere else.
Escape—{3}{B}{B}, Exile five other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.)

Rilsa Rael, Kingpin

Deathtouch
When Rilsa Rael, Kingpin enters, you take the initiative.
Whenever you attack, target attacking creature gains deathtouch until end of turn. If you've completed a dungeon, that creature also gets +5/+0 and gains first strike and menace until end of turn.

Dungeoneer's Pack

Dungeoneer's Pack enters tapped.
{2}, {T}, Sacrifice Dungeoneer's Pack: You take the initiative, gain 3 life, draw a card, and create a Treasure token. Activate only as a sorcery. (A Treasure token is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")