Thryx, the Sudden Storm

Flash
Flying
Spells you cast with mana value 5 or greater cost {1} less to cast and can't be countered.

Wizard's Retort

This spell costs {1} less to cast if you control a Wizard.
Counter target spell.

Galecaster Colossus

Tap an untapped Wizard you control: Return target nonland permanent you don't control to its owner's hand.

Invasion of the Giants

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Scry 2.
II — Draw a card. Then you may reveal a Giant card from your hand. When you do, Invasion of the Giants deals 2 damage to target opponent or planeswalker.
III — The next Giant spell you cast this turn costs {2} less to cast.

Cragganwick Cremator

When Cragganwick Cremator enters, discard a card at random. If you discard a creature card this way, Cragganwick Cremator deals damage equal to that card's power to target player or planeswalker.

Aegar, the Freezing Flame

Whenever a creature or planeswalker an opponent controls is dealt excess damage, if a Giant, Wizard, or spell you controlled dealt damage to it this turn, draw a card.

Borderland Behemoth

Trample
Borderland Behemoth gets +4/+4 for each other Giant you control.

Frost Titan

Whenever Frost Titan becomes the target of a spell or ability an opponent controls, counter that spell or ability unless its controller pays {2}.
Whenever Frost Titan enters or attacks, tap target permanent. It doesn't untap during its controller's next untap step.

Glimpse the Cosmos

Look at the top three cards of your library. Put one of them into your hand and the rest on the bottom of your library in any order.
As long as you control a Giant, you may cast Glimpse the Cosmos from your graveyard by paying {U} rather than paying its mana cost. If you cast Glimpse the Cosmos this way and it would be put into your graveyard, exile it instead.

Stinkdrinker Daredevil

Giant spells you cast cost {2} less to cast.

Quakebringer

Your opponents can't gain life.
At the beginning of your upkeep, Quakebringer deals 2 damage to each opponent. This ability triggers only if Quakebringer is on the battlefield or if Quakebringer is in your graveyard and you control a Giant.
Foretell {2}{R}{R}

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Stomp

Damage can't be prevented this turn. Stomp deals 2 damage to any target.

Bonecrusher Giant

Whenever Bonecrusher Giant becomes the target of a spell, Bonecrusher Giant deals 2 damage to that spell's controller.

Bonecrusher Giant // Stomp

Giant Harbinger

When Giant Harbinger enters, you may search your library for a Giant card, reveal it, then shuffle and put that card on top.

Calamity Bearer

If a Giant source you control would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Basalt Ravager

When Basalt Ravager enters, it deals X damage to any target, where X is the greatest number of creatures you control that have a creature type in common.

Surtland Flinger

Whenever Surtland Flinger attacks, you may sacrifice another creature. When you do, Surtland Flinger deals damage equal to the sacrificed creature's power to any target. If the sacrificed creature was a Giant, Surtland Flinger deals twice that much damage instead.

Crush Underfoot

Choose a Giant creature you control. It deals damage equal to its power to target creature.

Mizzium Mortars

Mizzium Mortars deals 4 damage to target creature you don't control.
Overload {3}{R}{R}{R} (You may cast this spell for its overload cost. If you do, change "target" in its text to "each.")

Inferno Titan

{R}: Inferno Titan gets +1/+0 until end of turn.
Whenever Inferno Titan enters or attacks, it deals 3 damage divided as you choose among one, two, or three targets.

Cyclone Summoner

When Cyclone Summoner enters, if you cast it from your hand, return all permanents to their owners' hands except for Giants, Wizards, and lands.

Fire Giant's Fury

Target Giant you control gets +2/+2 and gains trample until end of turn. Whenever it deals combat damage to a player this turn, exile that many cards from the top of your library. Until the end of your next turn, you may play those cards.

Thundercloud Shaman

When Thundercloud Shaman enters, it deals damage equal to the number of Giants you control to each non-Giant creature.

Star of Extinction

Destroy target land. Star of Extinction deals 20 damage to each creature and each planeswalker.

Surtland Elementalist

As an additional cost to cast this spell, reveal a Giant card from your hand or pay {2}.
Whenever Surtland Elementalist attacks, you may cast an instant or sorcery spell from your hand without paying its mana cost.

Awaken the Ancient

Enchant Mountain
Enchanted Mountain is a 7/7 red Giant creature with haste. It's still a land.

Herald's Horn

As Herald's Horn enters, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Battle of Frost and Fire

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Battle of Frost and Fire deals 4 damage to each non-Giant creature and each planeswalker.
II — Scry 3.
III — Whenever you cast a spell with mana value 5 or greater this turn, draw two cards, then discard a card.

Sunrise Sovereign

Other Giant creatures you control get +2/+2 and have trample.

Tectonic Giant

Whenever Tectonic Giant attacks or becomes the target of a spell an opponent controls, choose one —
• Tectonic Giant deals 3 damage to each opponent.
• Exile the top two cards of your library. Choose one of them. Until the end of your next turn, you may play that card.

Squash

This spell costs {3} less to cast if you control a Giant.
Squash deals 6 damage to target creature or planeswalker.