Take Up the Shield

Put a +1/+1 counter on target creature. It gains lifelink and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Spirit Link

Enchant creature (Target a creature as you cast this. This card enters the battlefield attached to that creature.)
Whenever enchanted creature deals damage, you gain that much life.

Planar Ally

Flying
Whenever Planar Ally attacks, venture into the dungeon. (Enter the first room or advance to the next room.)

Spirited Companion

When Spirited Companion enters the battlefield, draw a card.

Celestial Unicorn

Whenever you gain life, put a +1/+1 counter on Celestial Unicorn.

Greatsword of Tyr

Whenever equipped creature attacks, put a +1/+1 counter on it and tap up to one target creature defending player controls.
Equip {W} ({W}: Attach to target creature you control. Equip only as a sorcery.)

Pressure Point

Battlefield Raptor

Minimus Containment

Enchant nonland permanent
Enchanted permanent is a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color," and it loses all other abilities. (If it was a creature, it's no longer a creature.)

Plains

Adamant Will

Target creature gets +2/+2 and gains indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Mesa Cavalier

Flying
When Mesa Cavalier enters the battlefield, you gain 2 life.

Stormfront Pegasus

Ranger's Hawk

Flying
{3}, {T}, Tap another untapped creature you control: Venture into the dungeon. Activate only as a sorcery. (Enter the first room or advance to the next room.)

Veteran Dungeoneer

When Veteran Dungeoneer enters the battlefield, venture into the dungeon. (Enter the first room or advance to the next room.)