Optimistic Scavenger

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, put a +1/+1 counter on target creature.

Giant Inheritance

Enchant creature
Enchanted creature gets +5/+5 and has "Whenever this creature attacks, create a Monster Role token attached to up to one target attacking creature." (Enchanted creature gets +1/+1 and has trample.)
When this Aura is put into a graveyard from the battlefield, return it to its owner's hand.

Academy Researchers

When this creature enters, you may put an Aura card from your hand onto the battlefield attached to this creature.

Auramancer

When this creature enters, you may return target enchantment card from your graveyard to your hand.

Mesa Enchantress

Whenever you cast an enchantment spell, you may draw a card.

Songbirds' Blessing

Enchant creature
Whenever enchanted creature attacks, reveal cards from the top of your library until you reveal an Aura card. You may put that card onto the battlefield. If you don't, put it into your hand. Put the rest on the bottom of your library in a random order.

Gigantiform

Kicker {4}
Enchant creature
Enchanted creature has base power and toughness 8/8 and has trample.
When this Aura enters, if it was kicked, you may search your library for a card named Gigantiform, put it onto the battlefield, then shuffle.

Ephara, Ever-Sheltering

Ephara has lifelink and indestructible as long as you control at least three other enchantments.
Whenever another enchantment you control enters, draw a card.

Invasion of Theros

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, search your library for an Aura, God, or Demigod card, reveal it, put it into your hand, then shuffle.

Invasion of Theros // Ephara, Ever-Sheltering

Arcanum Wings

Enchant creature
Enchanted creature has flying.
Aura swap {2}{U} ({2}{U}: Exchange this Aura with an Aura card in your hand.)

Almost Perfect

Enchant creature
Enchanted creature has base power and toughness 9/10 and has indestructible.

Slumbering Keepguard

Whenever an enchantment you control enters, scry 1.
{2}{W}: This creature gets +1/+1 until end of turn for each enchantment you control.

Arcane Artisan

{2}{U}, {T}: Target player draws a card, then exiles a card from their hand. If a creature card is exiled this way, that player creates a token that's a copy of that card.
When this creature leaves the battlefield, exile all tokens created with it at the beginning of the next end step.

Octopus Umbra

Enchant creature
Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Sleep-Cursed Faerie

Flying, ward {2}
This creature enters tapped with three stun counters on it. (If it would become untapped, remove a stun counter from it instead.)
{1}{U}: Untap this creature.

Moon-Blessed Cleric

Divine Intervention — When this creature enters, you may search your library for an enchantment card, reveal it, then shuffle and put that card on top.

Eidolon of Astral Winds

Vigilance
Constellation — Whenever this creature or another enchantment you control enters, choose target creature you control. Until end of turn, that creature has base power and toughness 4/4 and gains flying.

Slippery Bogle

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Monk Idealist

When this creature enters, return target enchantment card from your graveyard to your hand.

Psemilla, Meletian Poet

Whenever you cast your first enchantment spell each turn, create a 2/2 white Nymph enchantment creature token.
At the beginning of each combat, if you control five or more enchantments, Psemilla gets +4/+4 and gains lifelink until end of turn. (Damage dealt by this creature also causes you to gain that much life.)

Pollenbright Wings

Enchant creature
Enchanted creature has flying.
Whenever enchanted creature deals combat damage to a player, create that many 1/1 green Saproling creature tokens.

Eldrazi Conscription

Enchant creature
Enchanted creature gets +10/+10 and has trample and annihilator 2. (Whenever it attacks, defending player sacrifices two permanents of their choice.)