Spellcasting. His spellcasting ability is Intelligence (spell save DC 16, +6 to hit with spell attacks).

Cantrips (at will): chill touch, fire bolt, frostbite

1st level (4 slots): frost fingers, shield, snare

2nd level (3 slots): earthbind, magic weapon, mind spike

3rd level (3 slots): counterspell, erupting earth, life transference, thunder step, water breathing

4th level (1 slots): ice storm, wall of fire

Last breaths fear: Any creatures within 40 feet reduces by one state it's resistances and immunities(Immunitites become resistances and resistances are negated). Also, any damage taken within this zone gets added 1d8 (1d8) Cold damage.

Multiattack. Zar'Yak makes three sword attacks.

Generals Duty. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 14 (2d6+7) slashing damage.

Frost Brand Greatsword. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 18 (3d6+7) cold damage.

Cold Breath (Recharge 5–6). The dragon exhales an icy blast in a 20-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 27 (6d8) cold damage on a failed save, or half as much damage on a successful one.

Zar'Yak can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. Zar'Yak regains spent legendary actions at the start of its turn.

Glacial Break(Costs 1 Action): Zar'Yak makes an attack to all creatures within 5 feet pushing them back 10 feet and dealing 1d6 Cold damage.

Out of your shell(Costs 2 Actions): Dashes towards a creature within 30 feet and causes their soul to be seperated from their body dealing 2d6 Cold damage. If they succeed on a DC 18 Wisdom check their soul gets pushed back 15 feet or, on a failed save, it gets pushed back 30 feet.