Cryogen

Cryogen
Statistics
Type	Boss
Environment	Snow Biome
AI Type	Cryogen AI
Damage	60 / 96 / 100 / 144 (melee) 25 / 100 / 105 / 150 (ice shield) 46 / 80 / 84 / 120 (frost blast) 52 / 92 / 96 / 138 (ice shard) 88 / 92 / 132 (ice bomb)
Max Life	17,900 / 28,640 / 32,400 / 49,200
Defense (DR)	10 (35% DR)
KB Resist	100%
Inflicts debuff	Frostburn 20% / 33% chance
Debuff duration	1.67 seconds
Debuff tooltip	It's either really hot or really cold. Either way it REALLY hurts.
Immune to:	All debuffs except:
Item (Quantity) Rate Soul of Might • 20-40 / 25-40 100% Frigid Bar • 15-24 100% Essence of Eleum • 3-5 100% Frost Core 100% Bittercold Staff 25% / 33% Effluvium Bow 25% / 33% Glacial Crusher 25% / 33% Icebreaker 25% / 33% Ice Star • 100-150 25% / 33% Permafrost 25% / 33% Snowstorm Staff 25% / 33% Cryo Stone 10% Frozen Key 20% Greater Healing Potion • 1-15 100% Cryogen Mask 14.29% Cryogen Trophy 10% Cryogen (Lore) • Always on first kill 100% Treasure Bag (Cryogen) • in Expert Mode only 100%
Map Icon

"The ancient ice spirits have been unbound!"

Cryogen is a Hardmode boss fought in the Snow biome.

Spawn

Cryogen does not spawn on its own and requires the player to summon it with a Cryo Key while in the Snow biome at any time of day.

Behavior

Cryogen has six phases, each of which has its own attack pattern and AI. Cryogen also spawns with a shield with 2000 health; this shield must be destroyed to directly attack Cryogen and will regenerate shortly after being destroyed.

Attacks

Phase 1

• Teleports and fires a random star-shaped barrage of frost bolts.
• Summons Cryocores upon taking damage.

Phase 2

• It will begin to rain/snow.
• Cryogen attempts to fly above the player and rain icicles down on them.
• Fires a barrage of frost bolts.
• Summons Aurora Spirits upon taking damage.

Phase 3

• Cryogen tries to ram into the player.
• Fires barrages of frost bolts and ice shards.
• Continuously summons Cryocores, regardless of damage taken.

Phase 4

• Cryogen gets faster and still tries to ram the player.
• Fires barrages of frost bolts.
• Cryocores are buffed from this phase onward.
• Continuously summons Aurora Spirits, regardless of damage taken.

Phase 5

• Cryogen now teleports near the player from time to time while continuing his other attacks.

Phase 6

• Cryogen starts derping out and randomly spinning while trying to ram the player erratically.
• Fires frost bolts and ice shards at high velocity.
• The rain/snow will stop when Cryogen is defeated.

In Expert Mode

• Cryogen gains massive attack and defense boosts as health depletes.

In Revengeance Mode

• Gains the ability to inflict the Chilled and Frozen debuffs and fires projectiles faster.

In Death Mode

• Summons more minions in all phases.

Summons

Image	Name	Condition
	Aurora Spirit	Phase 2 & above
	Cryocore	All phases

Aftermath

• When Cryogen is defeated for the first time, Cryonic Ore spawns in the Underground Snow biome.

Tips

• Drink a Warmth Potion before the start of the battle, as this will reduce the cold damage caused by the debuffs that its projectiles can cause.
• An Ankh Shield can grant complete immunity to Chilled.
• Do not stray too far or fly too high during the fight, as Cryogen will become immune to all damage if the player is not within the Snow biome.
• A wide arena with several levels of platforms can help with dodging his attacks. Putting in one or two minor platforms of solid blocks can help protect you and allow you to change direction when dealing with his second phase.
• If you're moving slowly on a platform you can keep Cryogen above you which can be useful for dealing quick damage with ranged weapons; make sure to have a way of dodging him when he comes too close.
• Avoid being hit by Cryogen and his icicles at all costs, as the Glacial State inflicted by them could lead to the player becoming stunlocked and easy prey to Cryogen's attacks.

Trivia

• Cryogen's theme is Antarctic Reinforcement, which was composed by the artist DM DOKURO.

Lore

Yharim's prison for the magic of the ice castle, Cryogen, is a representation of Yharim's bitter cold hatred for the Archmage of Ice. When Yharim was young, he ventured from the jungle temple to the ancient ice temple where the archmage Permafrost resided. Yharim asked to learn from him in order to "peacefully" calm the denizens of the underworld. But the archmage saw through his ruse and viewed only bitter contempt within Yharim's heart and the fiery urge to annihilate the underworld obsidian towers and their inhabitants. When the archmage refused Yharim kindly took his leave, bowing to the archmage and returning to his home. However, the archmage had not realized that Yharim had a contingency plan in place; Yharim had expertly placed magical runes hidden in a pocket dimension right outside the ice temple. Within minutes after Yharim took his leave, he activated the runes, causing the entire ice temple to be enveloped in pure darkness. Cryogen is what remains, a mindless frozen structure that was once trapped by Yharim due to its uncontrollable nature and powerful magic. Little does the Terrarian know that defeating the Wall of Flesh will rouse far more than mere spirits upon its' defeat...