Frostpyre Arcanist

This spell costs {1} less to cast if you control a Giant or a Wizard.
When Frostpyre Arcanist enters, search your library for an instant or sorcery card with the same name as a card in your graveyard, reveal it, put it into your hand, then shuffle.

Behold the Multiverse

Scry 2, then draw two cards.
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.)

Giant's Grasp

Enchant Giant you control
When Giant's Grasp enters, gain control of target nonland permanent for as long as Giant's Grasp remains on the battlefield.

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.

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.

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.

Goldvein Pick

Equipped creature gets +1/+1.
Whenever equipped creature deals combat damage to a player, create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

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.

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}

Lavaglide Pathway

Riverglide Pathway

Riverglide Pathway // Lavaglide Pathway

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.

Toralf's Hammer

Equipped creature has "{1}{R}, {T}, Unattach Toralf's Hammer: It deals 3 damage to any target. Return Toralf's Hammer to its owner's hand."
Equipped creature gets +3/+0 as long as it's legendary.
Equip {1}{R}

Toralf, God of Fury

Trample
Whenever a creature or planeswalker an opponent controls is dealt excess noncombat damage, Toralf deals damage equal to the excess to any target other than that permanent.

Toralf, God of Fury // Toralf's Hammer

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. Shivan Reef deals 1 damage to you.

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

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.

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.

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.)

Surtland Frostpyre

Surtland Frostpyre enters tapped.
{T}: Add {R}.
{2}{U}{U}{R}, {T}, Sacrifice Surtland Frostpyre: Scry 2. Surtland Frostpyre deals 2 damage to each creature. Activate only as a sorcery.

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.

Island

Provoke the Trolls

Provoke the Trolls deals 3 damage to any target. If a creature is dealt damage this way, it gets +5/+0 until end of turn.

Seize the Spoils

As an additional cost to cast this spell, discard a card.
Draw two cards and create a Treasure token. (It's an artifact with "{T}, Sacrifice this artifact: Add one mana of any color.")

Temple of Epiphany

Temple of Epiphany enters tapped.
When Temple of Epiphany enters, scry 1.
{T}: Add {U} or {R}.

Squash

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