Authority of the Consuls

Creatures your opponents control enter tapped.
Whenever a creature an opponent controls enters, you gain 1 life.

Calix, Destiny's Hand

+1: Look at the top four cards of your library. You may reveal an enchantment card from among them and put that card into your hand. Put the rest on the bottom of your library in a random order.
−3: Exile target creature or enchantment you don't control until target enchantment you control leaves the battlefield.
−7: Return all enchantment cards from your graveyard to the battlefield.

Estrid, the Masked

+2: Untap each enchanted permanent you control.
−1: Create a white Aura enchantment token named Mask attached to another target permanent. The token has enchant permanent and umbra armor.
−7: Mill seven cards. Return all non-Aura enchantment cards from your graveyard to the battlefield, then do the same for Aura cards.
Estrid, the Masked can be your commander.

All That Glitters

Enchant creature
Enchanted creature gets +1/+1 for each artifact and/or enchantment you control.

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Hullbreacher

Flash
If an opponent would draw a card except the first one they draw in each of their draw steps, instead you create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")