Cryomancer

icey

Cyromancy Savant

Beginning when you select this school at 3nd level, the gold and time you must spend to copy a spell into your spellbook is halved, provided that spell has cold as a listed damage type.

Verglas Coating

Beginning at 3nd level, you invoke latent thermodynamics to manipulate heat around you. When you deal damage with a leveled wizard spell, provided at least one target receives 4 damage, a willing creature of your choice within 30ft receives 1d4 + 4 temporary hit points for 10 minutes.

Resonant Damping

Starting at 6rd level, your icy magic slows the world down to a crawl. Whenever you deal cold damage to a creature, you may have that creature lose 10 feet of movement speed for 1 minute. This effect occurs once per creature hit per spell per turn. Additional iterations of this effect are cumulative, and if a creature's speed becomes zero or lower this way, they become Frozen. A creature that is Frozen is restrained.

At the end of each of their turns, a Frozen creature makes a Strength save against your spell casting DC to attempt to break free of the ice. If they succeed, their speed is returned to normal and they must have it lowered again to become Frozen once more.

Cryostasis

Beginning at 10th level, you no longer age naturally. In addition, you no longer require food or water, instead drawing on the heat in the atmosphere to sustain yourself. As a result, plants frost and wither as you pass, hoarfrost follows your footfall, and bodies of water freeze under you. This is expressed as though Water Walk has been cast on you, for any liquid surface below 100°F.

If a medium or larger body of water is within 10ft, you may cast Cone of Cold a number of times equal to half your proficiency modifier, rounded down. This resets when you finish a long rest. You can also cast this spells using any spell slots you have of the appropriate level. Under the DM's discretion, depending on the size of the body of water, this spell's effect may be expressed as if it were cast using a spell slot of a higher level. If a creature takes more than 60 damage from this spell and is killed, the resulting frozen statue never thaws. It is otherwise treated as a magical statue with no other effects.

Through considerable effort, you are able to enter and swim through liquids, represented by a concentration saving throw every minute. If you lose concentration, you rise to the surface of the liquid at a rate of 60 feet per round.

Frozen Shelter

Beginning at 14th level, you weave unseen threads into a frozen cocoon to protect your allies. As an action, you can generate a 10-foot-radius immobile dome of force around and above you. The spell ends if you leave its area.

Nine creatures of Medium size or smaller can fit inside the dome with you. The spell fails if its area includes a larger creature or more than nine creatures. Creatures and objects of your choice within the dome when you activate this feature can move through it freely. All other creatures and objects are barred from passing through it. Spells and other magical effects can’t extend through the dome or be cast through it. The dome has 45 hit points and is resistant to non-magical attacks. It can also be shattered with a Strength check of double your spell save DC. For the purposes of Shatter, this dome takes half damage.

The atmosphere inside the space is comfortable and dry, regardless of the weather outside. All creatures can breathe freely within the space. While inside the dome and for 10 minutes after, creatures of your choice gain 3d8+INT temporary hit points.
Until the effect ends, you can command the interior to become dimly lit or dark. The dome is opaque from the outside, appearing as an icy cocoon, but is transparent from the inside. The dome lasts for 1 minute, and can be used once per long rest.