Nylea's Colossus

Constellation — Whenever Nylea's Colossus or another enchantment you control enters, double target creature's power and toughness until end of turn.

Mazzy, Truesword Paladin

Whenever an enchanted creature attacks one of your opponents, it gets +2/+0 and gains trample until end of turn.
Whenever an Aura you control is put into your graveyard from the battlefield, exile it. Until the end of your next turn, you may cast that card.

Setessan Skirmisher

Constellation — Whenever an enchantment you control enters, Setessan Skirmisher gets +1/+1 until end of turn.

Setessan Champion

Constellation — Whenever an enchantment you control enters, put a +1/+1 counter on Setessan Champion and draw a card.

Captivating Unicorn

Constellation — Whenever an enchantment you control enters, tap target creature an opponent controls.

Enchantress's Presence

Whenever you cast an enchantment spell, draw a card.

Strength from the Fallen

Constellation — Whenever Strength from the Fallen or another enchantment you control enters, target creature gets +X/+X until end of turn, where X is the number of creature cards in your graveyard.

Nexus Wardens

Reach
Constellation — Whenever an enchantment you control enters, you gain 2 life.

Goldenhide Ox

Constellation — Whenever Goldenhide Ox or another enchantment you control enters, target creature must be blocked this turn if able.

Harvestguard Alseids

Constellation — Whenever Harvestguard Alseids or another enchantment you control enters, prevent all damage that would be dealt to target creature this turn.

Pious Wayfarer

Constellation — Whenever an enchantment you control enters, target creature gets +1/+1 until end of turn.

Draconic Destiny

Enchant creature
Enchanted creature gets +1/+1 and has flying, haste, and "{1}: This creature gets +1/+0 until end of turn." It's a Dragon in addition to its other types.
When enchanted creature dies, return Draconic Destiny to its owner's hand.

Eidolon of Blossoms

Constellation — Whenever Eidolon of Blossoms or another enchantment you control enters, draw a card.

Sythis, Harvest's Hand

Whenever you cast an enchantment spell, you gain 1 life and draw a card.

Humbler of Mortals

Constellation — Whenever Humbler of Mortals or another enchantment you control enters, creatures you control gain trample until end of turn.

Danitha, Benalia's Hope

First strike, vigilance, lifelink
When Danitha, Benalia's Hope enters, you may put an Aura or Equipment card from your hand or graveyard onto the battlefield attached to Danitha.

Favored of Iroas

Constellation — Whenever an enchantment you control enters, Favored of Iroas gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Skybind

Constellation — Whenever Skybind or another enchantment you control enters, exile target nonenchantment permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Ethereal Armor

Enchant creature
Enchanted creature gets +1/+1 for each enchantment you control and has first strike.

Stangg, Echo Warrior

Whenever Stangg, Echo Warrior attacks, create Stangg Twin, a legendary 3/4 red and green Human Warrior creature token. It enters tapped and attacking. For each Aura and Equipment attached to Stangg, create a token that's a copy of it attached to Stangg Twin. Sacrifice all tokens created this way at the beginning of the next end step.

Audacity

Enchant creature
Enchanted creature gets +2/+0 and has trample. (It can deal excess combat damage to the player or planeswalker it's attacking.)
When Audacity is put into a graveyard from the battlefield, draw a card.

Forgeborn Oreads

Constellation — Whenever Forgeborn Oreads or another enchantment you control enters, Forgeborn Oreads deals 1 damage to any target.

Nessian Wanderer

Constellation — Whenever an enchantment you control enters, look at the top three cards of your library. You may reveal a land card from among them and put that card into your hand. Put the rest on the bottom of your library in a random order.

Sram, Senior Edificer

Whenever you cast an Aura, Equipment, or Vehicle spell, draw a card.

Oakheart Dryads

Constellation — Whenever Oakheart Dryads or another enchantment you control enters, target creature gets +1/+1 until end of turn.