Adeline, Resplendent Cathar

Vigilance
Adeline, Resplendent Cathar's power is equal to the number of creatures you control.
Whenever you attack, for each opponent, create a 1/1 white Human creature token that's tapped and attacking that player or a planeswalker they control.

Cavern of Souls

As Cavern of Souls enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type, and that spell can't be countered.

Thalia's Lieutenant

When Thalia's Lieutenant enters, put a +1/+1 counter on each other Human you control.
Whenever another Human you control enters, put a +1/+1 counter on Thalia's Lieutenant.

Soul Warden

Whenever another creature enters, you gain 1 life.

Wedding Festivity

Wedding Announcement

At the beginning of your end step, put an invitation counter on Wedding Announcement. If you attacked with two or more creatures this turn, draw a card. Otherwise, create a 1/1 white Human creature token. Then if Wedding Announcement has three or more invitation counters on it, transform it.

Wedding Announcement // Wedding Festivity

Eiganjo, Seat of the Empire

{T}: Add {W}.
Channel — {2}{W}, Discard Eiganjo, Seat of the Empire: It deals 4 damage to target attacking or blocking creature. This ability costs {1} less to activate for each legendary creature you control.

Thalia, Guardian of Thraben

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

Soul's Attendant

Whenever another creature enters, you may gain 1 life.

Serra Ascendant

Lifelink (Damage dealt by this creature also causes you to gain that much life.)
As long as you have 30 or more life, Serra Ascendant gets +5/+5 and has flying.

Aether Vial

At the beginning of your upkeep, you may put a charge counter on Aether Vial.
{T}: You may put a creature card with mana value equal to the number of charge counters on Aether Vial from your hand onto the battlefield.

Plains

Auriok Champion

Protection from black and from red
Whenever another creature enters, you may gain 1 life.

Esper Sentinel

Whenever an opponent casts their first noncreature spell each turn, draw a card unless that player pays {X}, where X is Esper Sentinel's power.

Champion of the Parish

Whenever another Human enters under your control, put a +1/+1 counter on Champion of the Parish.