Captivating Unicorn

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

Brine Giant

This spell costs {1} less to cast for each enchantment you control.

Tuvasa the Sunlit

Tuvasa the Sunlit gets +1/+1 for each enchantment you control.
Whenever you cast your first enchantment spell each turn, draw a card.

Multani's Decree

Destroy all enchantments. You gain 2 life for each enchantment destroyed this way.

Ethereal Armor

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

Triton Waverider

Constellation — Whenever an enchantment you control enters, Triton Waverider gains flying until end of turn.

Yavimaya Enchantress

Yavimaya Enchantress gets +1/+1 for each enchantment on the battlefield.

Harvestguard Alseids

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

Thassa's Devourer

Constellation — Whenever Thassa's Devourer or another enchantment you control enters, target player mills two cards.

Humbler of Mortals

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

Pious Wayfarer

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

Nexus Wardens

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

Setessan Skirmisher

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

Oakheart Dryads

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

Ancestral Mask

Enchant creature
Enchanted creature gets +2/+2 for each other enchantment on the battlefield.