Breeches, Brazen Plunderer

Mana cost: {3}{R}
Type: Legendary Creature — Goblin Pirate
Power / toughness: 3 / 3
Set: Special Guests #6 (uncommon)
Price: $5.98 USD

Menace
Whenever one or more Pirates you control deal damage to your opponents, exile the top card of each of those opponents' libraries. You may play those cards this turn, and you may spend mana as though it were mana of any color to cast those spells.
Partner (You can have two commanders if both have partner.)

Breeches, Brazen Plunderer has 5 printings, first in Commander Legends (2020). EDHREC ranks it #4,804 among Commander cards. It appears most in Edward Kenway decks (6,553 on EDHREC). 1 public deck on TCG runs it. It has 12 official rulings.

Legality

commander: legal
legacy: legal
vintage: legal
pauper: not legal
modern: not legal
pioneer: not legal
standard: not legal
brawl: not legal

Public decks that run Breeches, Brazen Plunderer

Ahoy Mateys - The Lost Caverns of Ixalan Commander, led by Admiral Brass, Unsinkable

Commanders that run Breeches, Brazen Plunderer most

Deck counts from EDHREC.

Edward Kenway: 6,553 decks
Admiral Brass, Unsinkable: 5,733 decks
Don Andres, the Renegade: 4,599 decks
Admiral Beckett Brass: 3,436 decks
Vaan, Street Thief: 1,052 decks
Ragavan, Nimble Pilferer: 995 decks
Captain Storm, Cosmium Raider: 380 decks
Mary Read and Anne Bonny: 263 decks

Often played with Breeches, Brazen Plunderer

Cards that show up in the same decks on EDHREC.

Rulings

2020-11-10: Both commanders start in the command zone, and the remaining 98 cards (or 58 cards in a Commander Draft game) of your deck are shuffled to become your library.
2020-11-10: You can choose two commanders with partner that are the same color or colors. In Commander Draft, you can even choose two of the same commander with partner if you drafted them. If you do this, make sure you keep the number of times you've cast each from the command zone clear for "commander tax" purposes.
2020-11-10: If something refers to your commander while you have two commanders, it refers to one of them of your choice. If you are instructed to perform an action on your commander (e.g. put it from the command zone into your hand due to Command Beacon), you choose one of your commanders at the time the effect happens.
2020-11-10: An effect that checks whether you control your commander is satisfied if you control one or both of your two commanders.
2020-11-10: If you don't play one of the exiled cards, it remains exiled. It won't be available to be played on future turns.
2020-11-10: In a multiplayer game, if a player leaves the game, all cards that player owns leave as well. If you leave the game, any spells and/or permanents you control from Breeches's brazen thievery are exiled.
2020-11-10: You must follow the normal timing permissions and restrictions for each exiled card. If one is a land, you can't play it unless you have land plays available.
2020-11-10: Once the game begins, your two commanders are tracked separately. If you cast one, you won't have to pay an additional {2} the first time you cast the other. A player loses the game after having been dealt 21 damage from any one of them, not from both of them combined.
2020-11-10: You'll exile a card from each opponent who was dealt damage, not from all of your opponents.
2020-11-10: You'll still pay all costs for a spell cast this way, including additional costs. You may also pay alternative costs if any are available.
2020-11-10: To have two commanders, both must have the partner ability as the game begins. Losing the ability during the game doesn't cause either to cease to be your commander.
2020-11-10: If your Commander deck has two commanders, you can only include cards whose own color identities are also found in your commanders' combined color identities. If Falthis and Kediss are your commanders, your deck may contain cards with black and/or red in their color identity, but not cards with green, white, or blue.