Mercurial Geists

Flying
Whenever you cast an instant or sorcery spell, Mercurial Geists gets +3/+0 until end of turn.

Impact Tremors

Whenever a creature enters the battlefield under your control, Impact Tremors deals 1 damage to each opponent.

Hammer Dropper

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Meteor Golem

When Meteor Golem enters the battlefield, destroy target nonland permanent an opponent controls.

Meteor Golem

When Meteor Golem enters the battlefield, destroy target nonland permanent an opponent controls.

Veil of Summer

Draw a card if an opponent has cast a blue or black spell this turn. Spells you control can’t be countered this turn. You and permanents you control gain hexproof from blue and from black until end of turn. (You and they can’t be the targets of blue or black spells or abilities your opponents control.)

Manifold Key

, : Untap another target artifact.
, : Target creature can’t be blocked this turn.

Diviner’s Lockbox

, : Choose a card name, then reveal the top card of your library. If that card has the chosen name, sacrifice Diviner’s Lockbox and draw three cards. Activate this ability only any time you could cast a sorcery.

Bond of Revival

Return target creature card from your graveyard to the battlefield. It gains haste until your next turn.

Biogenic Ooze

When Biogenic Ooze enters the battlefield, create a 2/2 green Ooze creature token.
At the beginning of your end step, put a +1/+1 counter on each Ooze you control.
: Create a 2/2 green Ooze creature token.

Biogenic Ooze

When Biogenic Ooze enters the battlefield, create a 2/2 green Ooze creature token.
At the beginning of your end step, put a +1/+1 counter on each Ooze you control.
: Create a 2/2 green Ooze creature token.

Hammer Dropper

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Dead Weight

Enchant creature
Enchanted creature gets -2/-2.

Ral’s Dispersal

Return target creature to its owner’s hand. You may search your library and/or graveyard for a card named Ral, Caller of Storms, reveal it, and put it into your hand. If you search your library this way, shuffle it.

Meteor Golem

When Meteor Golem enters the battlefield, destroy target nonland permanent an opponent controls.

Aviation Pioneer

When Aviation Pioneer enters the battlefield, create a 1/1 colorless Thopter artifact creature token with flying.

Grip of Phyresis

Gain control of target Equipment, then create a 0/0 black Germ creature token and attach that Equipment to it.

Bonus Round

Until end of turn, whenever a player casts an instant or sorcery spell, that player copies it and may choose new targets for the copy.

Sublime Exhalation

Undaunted (This spell costs less to cast for each opponent.)
Destroy all creatures.

Duelist’s Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

The Flame of Keld

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Discard your hand.
II — Draw two cards.
III — If a red source you control would deal damage to a permanent or player this turn, it deals that much damage plus 2 to that permanent or player instead.