Frost knights are warriors who are trained in a special kind of magic, that grants them the ability to manipulate the primordial power of ice, a branch of water elemental control. They use this magic, alongside with their martial abilities to gain an edge on battles. Not all creatures that have such power become frost knights, and anyone who choose this path and survive long enough are considered the chosen champions of their communities, being respected and feared for the connection and control they have over the destructive force of ice.

It is more common for frost knights to be native from arctic environments, due to the proximity with the elements they intend to control and since this magic was created by arctic tribes who devote elements of winter, but this is not a strict rule, and the power of frost can be controlled on any sort of environment.

Some of these warriors inherit the natural power to control frost, having in their bloodline the blood of ice giants or white dragons. Other's, however, seek for this power, diligently training for years to master it while attuning their senses to this ice magic.

Cantrips
frostbite, ray of frost, shape water.

1st-level
absorb elements, armor of agathys, frost fingers, ice knife.

2nd-level
rime's binding ice, hold person, snowball swarm, spike growth, warding wind.

3rd-level
elemental weapon (cold only), protection from energy, sleet storm, slow.

4th-level
conjure minor elementals (ice mephit only), elemental bane (cold only), fire shield, freedom of movement, ice storm.

For certain spells: Elemental weapon: Cold only | Conjure Minor Elementals: ice mephit only | Elemental Bane: Cold Only | Fire shield: Chill Shield only

Frost Knight’s Arsenal

Starting at 3rd level, you can create weapons made out of ice, by condensing thin air into shards of ice. As an object interaction or an action on your turn, you can create any type of simple or martial weapon. Also, you can create a piece of ammunition every time you make an attack with a weapon you are proficient with.

A weapon created by this ability lasts for 1 minute, but melts immediately if leaves your hand. A piece of ammunition breaks on impact. Also, any weapon created with this feature shatters on a roll of 1 or 20 on the d20.

Finally, the weapon created by the ice arsenal ignores resistance and immunity to non-magical bludgeoning, piercing and slashing damage against creatures without resistance or immunity to cold.

The number of equipment you can create equals 10 x your proficiency bonus pieces of ammunition; 3 x your proficiency bonus simple weapons; and your proficiency bonus martial weapons. You regain the ability to do so after finishing a long rest.

Frost Knight’s Bulwark

Starting at 7th level, you can shape ice into a magical shield on your free hand, as a bonus action, that last until the start of your next turn.

The shield grants you resistance to non-magical slashing, piercing and damage, and resistance to cold and fire damage.

Frostburn

Also at 7th level, you ignore resistance to cold damage when using your Frost Knight features.

In addition, when you cause cold damage against a creature immune to it, you can use your reaction to ignore the immunity. You can use this feature a number of times equal to your Wisdom modifier. You regain your uses after finishing a long rest

Improved Armaments

Starting at 10th level, your armaments increase in power. While you wield a weapon created by your Frost Knight Arsenal, that weapon have a bonus of +1 to attacks and damage rolls, and cause additional 1d4 cold damage on a hit. The damage is considered magical for the purposes of overcoming resistances and immunity to non-magical damage. If you wield a pair of weapons, choose one to benefit from this feature.

This increases to +2 and 1d6 at 15th level, and +3 and 1d8 at 18th level.

 

Winter Assault

At 15th level, whenever you use Action Surge, you can cast a Frost Knight spell with the casting time of an action as a bonus action.

Icy Transformation

Starting at 18th level, you can let the elemental power of ice infuse your body. You can cast the investiture of ice spell once, without spending a spell slot and without requiring concentration. Intelligence is your ability score for this spell.

While investiture of ice is active, you can forgo one of your Attacks made as part of the Attack action to use the Action granted by the spell.

Once you use this feature, you can't use it again until you finish a long rest.