Tawnos, Urza's Apprentice

Haste
{U}{R}, {T}: Copy target activated or triggered ability you control from an artifact source. You may choose new targets for the copy. (Mana abilities can't be targeted.)

Rakdos Cluestone

{T}: Add {B} or {R}.
{B}{R}, {T}, Sacrifice this artifact: Draw a card.

Urza, Prince of Kroog

Artifact creatures you control get +2/+2.
{6}: Create a token that's a copy of target artifact you control, except it's a 1/1 Soldier creature in addition to its other types.

Teysa Karlov

If a creature dying causes a triggered ability of a permanent you control to trigger, that ability triggers an additional time.
Creature tokens you control have vigilance and lifelink.

Reasonable Doubt

Counter target spell unless its controller pays {2}.
Suspect up to one target creature. (A suspected creature has menace and can't block.)

Izzet Cluestone

{T}: Add {U} or {R}.
{U}{R}, {T}, Sacrifice this artifact: Draw a card.

Oskar, Rubbish Reclaimer

This spell costs {1} less to cast for each different mana value among cards in your graveyard.
Whenever you discard a nonland card, you may cast it from your graveyard.

Garth One-Eye

{T}: Choose a card name that hasn't been chosen from among Disenchant, Braingeyser, Terror, Shivan Dragon, Regrowth, and Black Lotus. Create a copy of the card with the chosen name. You may cast the copy. (You still pay its costs.)

Azorius Cluestone

{T}: Add {W} or {U}.
{W}{U}, {T}, Sacrifice this artifact: Draw a card.

Orzhov Cluestone

{T}: Add {W} or {B}.
{W}{B}, {T}, Sacrifice this artifact: Draw a card.

Civic Saber

Equipped creature gets +1/+0 for each of its colors.
Equip {1}

Dawn's Truce

Gift a card (You may promise an opponent a gift as you cast this spell. If you do, they draw a card before its other effects.)
You and permanents you control gain hexproof until end of turn. If the gift was promised, permanents you control also gain indestructible until end of turn.

Boros Cluestone

{T}: Add {R} or {W}.
{R}{W}, {T}, Sacrifice this artifact: Draw a card.

Murder

Deadly Complication

Choose one or both —
• Destroy target creature.
• Put a +1/+1 counter on target suspected creature you control. You may have it become no longer suspected.