Path to Exile

Exile target creature. Its controller may search their library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Resolute Watchdog

Defender
{1}, Sacrifice Resolute Watchdog: Target creature you control gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Rampant Growth

Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Morska, Undersea Sleuth

You have no maximum hand size.
At the beginning of your upkeep, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you draw your second card each turn, put two +1/+1 counters on Morska, Undersea Sleuth.

They Went This Way

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Masked Vandal

Changeling (This card is every creature type.)
When Masked Vandal enters, you may exile a creature card from your graveyard. If you do, exile target artifact or enchantment an opponent controls.

Forensic Gadgeteer

Whenever you cast an artifact spell, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Activated abilities of artifacts you control cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

Root Out

Destroy target artifact or enchantment.
Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Martha Jones

Woman Who Walked the Earth — When Martha Jones enters, investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, Martha Jones and up to one other target creature can't be blocked this turn.
Doctor's companion (You can have two commanders if the other is the Doctor.)

Explore

You may play an additional land this turn.
Draw a card.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Tireless Provisioner

Landfall — Whenever a land you control enters, create a Food token or a Treasure token. (Food is an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life." Treasure is an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Rise and Shine

Target noncreature artifact you control becomes a 0/0 artifact creature. Put four +1/+1 counters on each artifact that became a creature this way.
Overload {4}{U}{U} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Faithful Watchdog

Vigilance
Faithful Watchdog enters with three +1/+1 counters on it.

Dogmeat, Ever Loyal

When Dogmeat enters, mill five cards, then return an Aura or Equipment card from your graveyard to your hand.
Whenever a creature you control that's enchanted or equipped attacks, create a Junk token. (It's an artifact with "{T}, Sacrifice this artifact: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Requisition Raid

Spree (Choose one or more additional costs.)
+ {1} — Destroy target artifact.
+ {1} — Destroy target enchantment.
+ {1} — Put a +1/+1 counter on each creature target player controls.

Phelia, Exuberant Shepherd

Flash
Whenever Phelia, Exuberant Shepherd attacks, exile up to one other target nonland permanent. At the beginning of the next end step, return that card to the battlefield under its owner's control. If it entered under your control, put a +1/+1 counter on Phelia.

Rex, Cyber-Hound

Whenever Rex, Cyber-Hound deals combat damage to a player, they mill two cards and you get {E}{E} (two energy counters).
Pay {E}{E}: Choose target creature card in a graveyard. Exile it with a brain counter on it. Activate only as a sorcery.
Rex has all activated abilities of all cards in exile with brain counters on them.

Revive the Shire

Return target permanent card from your graveyard to your hand. Create a Food token. (It's an artifact with "{2}, {T}, Sacrifice this artifact: You gain 3 life.")

Mischievous Pup

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, return up to one other target permanent you control to its owner's hand.

Alpine Watchdog

Vigilance (Attacking doesn't cause this creature to tap.)

Mushroom Watchdogs

Sacrifice a Food: Put a +1/+1 counter on Mushroom Watchdogs. It gains vigilance until end of turn. Activate only as a sorcery.

Wary Watchdog

When Wary Watchdog enters or dies, surveil 1. (Look at the top card of your library. You may put it into your graveyard.)

Deduce

Draw a card. Investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")

Rambunctious Mutt

When Rambunctious Mutt enters, destroy target artifact or enchantment an opponent controls.

Detective of the Month

Ascend (If you control ten or more permanents, you get the city's blessing for the rest of the game.)
As long as you have the city's blessing, Detectives you control can't be blocked.
Whenever you draw your second card each turn, create a 2/2 white and blue Detective creature token.

Trusty Retriever

When Trusty Retriever enters, choose one —
• Put a +1/+1 counter on Trusty Retriever.
• Return target artifact or enchantment card from your graveyard to your hand.

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Stroke of Midnight

Destroy target nonland permanent. Its controller creates a 1/1 white Human creature token.