Danitha Capashen, Paragon

First strike, vigilance, lifelink
Aura and Equipment spells you cast cost {1} less to cast.

Esper Sentinel

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

Ajani's Chosen

Whenever an enchantment you control enters, create a 2/2 white Cat creature token. If that enchantment is an Aura, you may attach it to the token.

Mesa Enchantress

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

Mountain

Sram, Senior Edificer

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

Archon of Sun's Grace

Flying
Lifelink (Damage dealt by this creature also causes you to gain that much life.)
Pegasus creatures you control have lifelink.
Constellation — Whenever an enchantment you control enters, create a 2/2 white Pegasus creature token with flying.

Cass, Hand of Vengeance

Vigilance
Whenever Cass or another creature you control dies, if it was enchanted or equipped, return any number of Aura cards that were attached to it from your graveyard to the battlefield attached to target creature, then attach any number of Equipment that were attached to it to that creature.

Mister Gutsy

Whenever you cast an Aura or Equipment spell, put a +1/+1 counter on this creature.
When this creature dies, create X Junk tokens, where X is the number of +1/+1 counters on it. (They're artifacts with "{T}, Sacrifice this token: Exile the top card of your library. You may play that card this turn. Activate only as a sorcery.")

Codsworth, Handy Helper

Commanders you control have ward {2}.
{T}: Add {W}{W}. Spend this mana only to cast Aura and/or Equipment spells.
{T}: Attach target Aura or Equipment you control to target creature you control. Activate only as a sorcery.

Kor Spiritdancer

This creature gets +2/+2 for each Aura attached to it.
Whenever you cast an Aura spell, you may draw a card.

Plains

Light-Paws, Emperor's Voice

Whenever an Aura you control enters, if you cast it, you may search your library for an Aura card with mana value less than or equal to that Aura and with a different name than each Aura you control, put that card onto the battlefield attached to Light-Paws, then shuffle.

Solemn Simulacrum

When this creature enters, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.
When this creature dies, you may draw a card.

Armory Paladin

Trample
Whenever you cast an Aura or Equipment spell, exile the top card of your library. You may play that card until the end of your next turn.