Might have

Araumi of the Dead Tide

{T}, Exile cards from your graveyard equal to the number of opponents you have: Target creature card in your graveyard gains encore until end of turn. The encore cost is equal to its mana cost. (Exile the creature card and pay its mana cost: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Have

Reaping the Graves

Return target creature card from your graveyard to your hand.
Storm (When you cast this spell, copy it for each spell cast before it this turn. You may choose new targets for the copies.)

Getting

Amphin Mutineer

When Amphin Mutineer enters the battlefield, exile up to one target non-Salamander creature. That creature's controller creates a 4/3 blue Salamander Warrior creature token.
Encore {4}{U}{U} ({4}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Seer's Sundial

Landfall — Whenever a land enters the battlefield under your control, you may pay {2}. If you do, draw a card.

Bloodghast

Bloodghast can't block.
Bloodghast has haste as long as an opponent has 10 or less life.
Landfall — Whenever a land enters the battlefield under your control, you may return Bloodghast from your graveyard to the battlefield.

Dread Return

Return target creature card from your graveyard to the battlefield.
Flashback—Sacrifice three creatures. (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lier, Disciple of the Drowned

Spells can't be countered.
Each instant and sorcery card in your graveyard has flashback. The flashback cost is equal to that card's mana cost.

Skeleton Crew

Each other creature you control that's a Skeleton or Pirate gets +1/+1.
Whenever one or more creature cards leave your graveyard, create a 2/2 black Skeleton Pirate creature token. (This ability triggers only from the battlefield.)
{5}{B}: Return Skeleton Crew from your graveyard to the battlefield tapped.

Corpses of the Lost

Skeletons you control get +1/+0 and have haste.
When Corpses of the Lost enters the battlefield, create a 2/2 black Skeleton Pirate creature token.
At the beginning of your end step, if you descended this turn, you may pay 1 life. If you do, return Corpses of the Lost to its owner's hand. (You descended if a permanent card was put into your graveyard from anywhere.)

Shipwreck Dowser

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Shipwreck Dowser enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Crafty Cutpurse

Flash
When Crafty Cutpurse enters the battlefield, each token that would be created under an opponent's control this turn is created under your control instead.

Songs of the Damned

Add {B} for each creature card in your graveyard.

Sinister Starfish

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Dark Ritual

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Merchant Raiders

Whenever Merchant Raiders or another Pirate enters the battlefield under your control, tap up to one target creature. That creature doesn't untap during its controller's untap step for as long as you control Merchant Raiders.

Soul Stair Expedition

Landfall — Whenever a land enters the battlefield under your control, you may put a quest counter on Soul Stair Expedition.
Remove three quest counters from Soul Stair Expedition and sacrifice it: Return up to two target creature cards from your graveyard to your hand.

Sunken Hollow

({T}: Add {U} or {B}.)
Sunken Hollow enters the battlefield tapped unless you control two or more basic lands.

Skeleton Key

Equipped creature has skulk. (It can't be blocked by creatures with greater power.)
Whenever equipped creature deals combat damage to a player, you may draw a card. If you do, discard a card.
Equip {2}

March of the Drowned

Choose one —
• Return target creature card from your graveyard to your hand.
• Return two target Pirate cards from your graveyard to your hand.

Body Double

You may have Body Double enter the battlefield as a copy of any creature card in a graveyard.

Filter Out

Return all noncreature, nonland permanents to their owners' hands.

The Indomitable

Trample
Whenever a creature you control deals combat damage to a player, draw a card.
Crew 3
You may cast The Indomitable from your graveyard as long as you control three or more tapped Pirates and/or Vehicles.

Terrain Generator

{T}: Add {C}.
{2}, {T}: You may put a basic land card from your hand onto the battlefield tapped.

Expedition Map

{2}, {T}, Sacrifice Expedition Map: Search your library for a land card, reveal it, put it into your hand, then shuffle.

Kitesail Skirmisher

Flying
Whenever Kitesail Skirmisher attacks, another target creature attacking the same player or planeswalker gains flying until end of turn.
Encore {4}{U} ({4}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Thought Scour

Target player mills two cards.
Draw a card.

Narcomoeba

Flying
When Narcomoeba is put into your graveyard from your library, you may put it onto the battlefield.

Forerunner of the Coalition

When Forerunner of the Coalition enters the battlefield, you may search your library for a Pirate card, reveal it, then shuffle and put that card on top.
Whenever another Pirate enters the battlefield under your control, each opponent loses 1 life.

Swamp

Staunch Crewmate

When Staunch Crewmate enters the battlefield, look at the top four cards of your library. You may reveal an artifact or Pirate card from among them and put it into your hand. Put the rest on the bottom of your library in a random order.

The Grim Captain

Menace, trample, lifelink, hexproof
Whenever The Grim Captain attacks, each opponent sacrifices a nonland permanent. Then you may put an exiled creature card used to craft The Grim Captain onto the battlefield under your control tapped and attacking.

Throne of the Grim Captain

{T}: Mill two cards.
Craft with a Dinosaur, a Merfolk, a Pirate, and a Vampire {4} ({4}, Exile this artifact, Exile the four from among permanents you control and/or cards in your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

Throne of the Grim Captain // The Grim Captain

Pitiless Plunderer

Whenever another creature you control dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Mire Triton

Deathtouch
When Mire Triton enters the battlefield, mill two cards and you gain 2 life.

Merfolk Looter

Ghost of Ramirez DePietro

Ghost of Ramirez DePietro can't be blocked by creatures with toughness 3 or greater.
Whenever Ghost of Ramirez DePietro deals combat damage to a player, choose up to one target card in a graveyard that was discarded or put there from a library this turn. Put that card into its owner's hand.
Partner (You can have two commanders if both have partner.)

Mesmeric Orb

Whenever a permanent becomes untapped, that permanent's controller mills a card.

Restless Reef

Restless Reef enters the battlefield tapped.
{T}: Add {U} or {B}.
{2}{U}{B}: Until end of turn, Restless Reef becomes a 4/4 blue and black Shark creature with deathtouch. It's still a land.
Whenever Restless Reef attacks, target player mills four cards.

Pirate's Cutlass

When Pirate's Cutlass enters the battlefield, attach it to target Pirate you control.
Equipped creature gets +2/+1.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Pirated Copy

You may have Pirated Copy enter the battlefield as a copy of any creature on the battlefield, except it's a Pirate in addition to its other types and it has "Whenever this creature or another creature with the same name deals combat damage to a player, you draw a card."

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Animate Dead

Enchant creature card in a graveyard
When Animate Dead enters the battlefield, if it's on the battlefield, it loses "enchant creature card in a graveyard" and gains "enchant creature put onto the battlefield with Animate Dead." Return enchanted creature card to the battlefield under your control and attach Animate Dead to it. When Animate Dead leaves the battlefield, that creature's controller sacrifices it.
Enchanted creature gets -1/-0.

Thought Erasure

Target opponent reveals their hand. You choose a nonland card from it. That player discards that card.
Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

The Grim Captain's Locker

{T}: Surveil 1. (Look at the top card of your library. You may put it into your graveyard.)
{T}: Until end of turn, each creature card in your graveyard gains "Escape—{3}{B}, Exile four other cards from your graveyard." (You may cast a card with escape from your graveyard for its escape cost.)

Salvager of Secrets

When Salvager of Secrets enters the battlefield, return target instant or sorcery card from your graveyard to your hand.

Rotting Regisaur

At the beginning of your upkeep, discard a card.

Trove Tracker

When Trove Tracker dies, draw a card.
Encore {5}{U}{U} ({5}{U}{U}, Exile this card from your graveyard: For each opponent, create a token copy that attacks that opponent this turn if able. They gain haste. Sacrifice them at the beginning of the next end step. Activate only as a sorcery.)

Grasping Scoundrel

Grasping Scoundrel gets +1/+0 as long as it's attacking.

Treasure Cruise

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Draw three cards.

Island

Spyglass Siren

Flying
When Spyglass Siren enters the battlefield, create a Map token. (It's an artifact with "{1}, {T}, Sacrifice this artifact: Target creature you control explores. Activate only as a sorcery.")

Francisco, Fowl Marauder

Flying
Francisco, Fowl Marauder can't block.
Whenever one or more Pirates you control deal damage to a player, Francisco explores.
Partner (You can have two commanders if both have partner.)