Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Refute

Counter target spell. Draw a card, then discard a card.

Geier Reach Sanitarium

{T}: Add {C}.
{2}, {T}: Each player draws a card, then discards a card.

Toluz, Clever Conductor

When Toluz, Clever Conductor enters, it connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on this creature.)
Whenever you discard one or more cards, exile them from your graveyard.
When Toluz dies, put the cards exiled with it into their owner's hand.

Frantic Search

Draw two cards, then discard two cards. Untap up to three lands.

Sol Ring

Kiora, the Rising Tide

When Kiora enters, draw two cards, then discard two cards.
Threshold — Whenever Kiora attacks, if there are seven or more cards in your graveyard, you may create Scion of the Deep, a legendary 8/8 blue Octopus creature token.

Homunculus Horde

Whenever you draw your second card each turn, create a token that's a copy of this creature.