Arcane Signet

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

Sol Ring

Lazav, Wearer of Faces

Whenever Lazav, Wearer of Faces attacks, exile target card from a graveyard, then investigate. (Create a Clue token. It's an artifact with "{2}, Sacrifice this artifact: Draw a card.")
Whenever you sacrifice a Clue, you may have Lazav become a copy of a creature card exiled with it until end of turn.

Erdwal Illuminator

Flying
Whenever you investigate for the first time each turn, investigate an additional time.

Likeness Looter

Flying
{T}: Draw a card, then discard a card.
{X}: Likeness Looter becomes a copy of target creature card in your graveyard with mana value X, except it has flying and this ability. Activate only as a sorcery.

Windfall

Each player discards their hand, then draws cards equal to the greatest number of cards a player discarded this way.

Buried Alive

Search your library for up to three creature cards, put them into your graveyard, then shuffle.