Backup Agent

When Backup Agent enters, put a +1/+1 counter on target creature.

Myrel, Shield of Argive

During your turn, your opponents can't cast spells or activate abilities of artifacts, creatures, or enchantments.
Whenever Myrel, Shield of Argive attacks, create X 1/1 colorless Soldier artifact creature tokens, where X is the number of Soldiers you control.

Coppercoat Vanguard

Each other Human you control gets +1/+0 and has ward {1}. (Whenever it becomes the target of a spell or ability an opponent controls, counter it unless that player pays {1}.)

Mountain

Mirror-Shield Hoplite

Vigilance
Whenever a creature you control becomes the target of a backup ability, copy that ability. You may choose new targets for the copy. This ability triggers only once each turn.

Plains

Baird, Argivian Recruiter

At the beginning of your end step, if you control a creature with power greater than its base power, create a 1/1 white Soldier creature token.

Wind-Scarred Crag

This land enters tapped.
When this land enters, you gain 1 life.
{T}: Add {R} or {W}.

Kayla's Reconstruction

Look at the top seven cards of your library. Put up to X artifact and/or creature cards with mana value 3 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.

Parish-Blade Trainee

Training (Whenever this creature attacks with another creature with greater power, put a +1/+1 counter on this creature.)
When Parish-Blade Trainee dies, put its counters on target creature you control.

Siege Veteran

At the beginning of combat on your turn, put a +1/+1 counter on target creature you control.
Whenever another nontoken Soldier you control dies, create a 1/1 colorless Soldier artifact creature token.

Search Party Captain

This spell costs {1} less to cast for each creature you attacked with this turn.
When Search Party Captain enters, draw a card.

Thalia, Guardian of Thraben

First strike
Noncreature spells cost {1} more to cast.

Strangle

Strangle deals 3 damage to target creature or planeswalker.

Loran's Escape

Target artifact or creature gains hexproof and indestructible until end of turn. Scry 1.

Sigiled Sentinel

Backup 1 (When this creature enters, put a +1/+1 counter on target creature. If that's another creature, it gains the following ability until end of turn.)
Vigilance