Mastered Elemental Bond: Ice

The bond with your elemental companion grows, furthering your mastery over the season of Winter and instilling a preternatural instinct for survival.

• When you make a Wisdom (Perception) check in a blizzard or dense fog, you count as having blindsight to a range of 60 feet.
• Survival Instinct: When you are reduced to 0 hit points, you may use a reaction to spend one hit die. You roll the hit die, and gain a number of temporary hit points equal to the amount rolled + your Constitution modifier + your Charisma modifier. These temporary hit points last for 1 minute, and you are considered to have gained them before you are reduced to 0 hit points, but after you would be required to make a Constitution saving throw to maintain concentration. While you have at least 1 of these temporary hit points remaining, you do not fall unconscious, you automatically pass any saving throws to avoid being charmed or frightened, and you have advantage on Constitution saving throws to maintain concentration. You also gain immunity to cold damage, and resistance to fire, poison and psychic damage for the duration. You cannot use this ability if the damage would be enough to cause instant death. You may use this ability once, regaining the use when you complete a long rest.
• Mastered Innate Spellcasting: You learn one of the following spells and may cast it once for free as if using a 3rd level spell slot, regaining the use when you complete a long rest: fog cloud, ice knife, hunter's mark, skywrite, Snilloc's snowball swarm, alter self, find steed, spike growth, glyph of warding, sleet storm, wall of water. Charisma is your spellcasting ability for this spell. You may swap this spell for a different one from this list when you gain a level.

If you select the spell alter self, you may only use the natural weapons part of the spell. When cast in this way, your natural weapons appear as claws, spines or horns of solid ice, and they deal an extra 1d4 cold damage.
If you select the spell find steed, the summoned creature is considered to be an ice elemental, and appears to be made of ice, snow, or similar material. Otherwise its statistics remain the same.
If you select the spell spike growth, the spikes appear as crystal-clear shards of ice.
If you select the spell glyph of warding, you may only use the explosive runes part of the spell, and the damage type you choose must be of an element to which you are bonded (ie. acid for water; cold for ice; fire for fire; lightning for lightning; thunder for air).
If you select the spell wall of water, the spell manifests as a wall of solid ice. See the spell's description for relevant rules. When cast in this way, each 5 foot section of wall has an AC bonus and gains additional hit points equal to your Charisma modifier. The wall is immune to cold damage, and vulnerable to fire and thunder damage.