Arventarax Aussir Marfedelom

Ice Walk. Arventarax can move across and climb icy surfaces without needing to make an ability check. Additionally, difficult terrain composed of ice or snow doesn't cost her extra movement.

Legendary Resistance (3/Day). If Arventarax fails a saving throw, she can choose to succeed instead.

Imbued Magics: Arventarax has been imbued with the following magical items and can use one of her choice as an action.

Ring of Spell Turning (1/Day). When a spell is directed at Arventarax  from a hostile creature she has advantage on saving throws against any spell that targets only her(not in an area of effect). In addition, if she rolls a 20 for the save and the spell is 7th level or lower, the spell has no effect on her and instead targets the caster, using the slot level, spell save DC, attack bonus, and spellcasting ability of the caster.

Rod of the Pact Keeper (1/Day). Arventarax  gains a +3 bonus to spell attack rolls and to the saving throw of her spells until she finishes her next long rest. In addition, she can regain 1 spell slot as an action. Once used she may cast one following warlock spells at 9th level:

• mind sliver spell save DC 23, (4d6) psychic damage.
• hex lasts for 24 hours.
• counterspell

Wand of Winter (1/Day). Arventarax can use her action to cast one of the following spells from the wand, even if she is incapable of casting spells at 9th level:

• ray of frost, cast at 5th level; (+9 to hit with ranged spell attack)
• sleet storm, spell save DC 17 (20 if Rod of the Pact Keeper is active)
• ice storm, spell save DC 17 (20 if Rod of the Pact Keeper is active)

Rod of Alertness(1/Day). Arventarax has advantage on perception checks and initiative rolls. She can also use an action to cast one of the following spells at 9th level:

• detect evil and good
• detect magic
• detect poison and disease
• see invisibility.

Staff of Frost (1/Day). Arventarax can use her action to cast one of the following spells from the staff at 9th level: 

• cone of cold spell DC 17 (20 if Rod of the Pact Keeper is active)
• fog cloud 180 foot radius
• ice storm spell save DC 17 (20 if Rod of the Pact Keeper is active)
• wall of ice spell save DC 17 (20 if Rod of the Pact Keeper is active)

Multiattack. Arventarax can use her Frightful Presence. She then makes three attacks: one with her bite and two with her claws.

Bite. Melee Weapon Attack: +14 to hit, reach 15 ft., one target. Hit: 19 (2d10 + 8) piercing damage plus 9 (2d8) cold damage.

Claw. Melee Weapon Attack: +14 to hit, reach 10 ft., one target. Hit: 15 (2d6 + 8) slashing damage.

Tail. Melee Weapon Attack: +14 to hit, reach 20 ft., one target. Hit: 17 (2d8 + 8) bludgeoning damage.

Frightful Presence. Each creature of Arventarax's choice that is within 120 feet of the dragon and aware of it must succeed on a DC 20 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature's saving throw is successful or the effect ends for it, the creature is immune to the dragon's Frightful Presence for the next 24 hours.

Cold Breath (Recharge 5–6). The dragon exhales an icy blast in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 72 (16d8) cold damage on a failed save, or half as much damage on a successful one.

Ring of Spell Turning (1/Day). When a spell is directed at Arventarax  from a hostile creature she has advantage on saving throws against any spell that targets only her(not in an area of effect). In addition, if she rolls a 20 for the save and the spell is 7th level or lower, the spell has no effect on her and instead targets the caster, using the slot level, spell save DC, attack bonus, and spellcasting ability of the caster.

Arventarax can take 4 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. The dragon regains spent legendary actions at the start of its turn.

Detect. Arventarax makes a Wisdom (Perception) check.

Tail Attack. Arventarax makes a tail attack.

Wing Attack (Costs 2 Actions). Arventarax beats its wings. Each creature within 15 feet of Arventarax must succeed on a DC 22 Dexterity saving throw or take 15 (2d6 + 8) bludgeoning damage and be knocked prone. Arventarax can then fly up to half its flying speed.

Imbued Magics(Costs 2 Actions). Arventarax may use one of her imbued magic items. She may use an item that has already been used this day as part of this legendary action.

When Aventarax drops below half of her hit point maximum she can take the below action as a legendary action until she either dies or is healed fully.

Cold Breath (Costs 2 Actions). Arventarax exhales an icy blast in a 90-foot cone. Each creature in that area must make a DC 22 Constitution saving throw, taking 72 [rollable](16d8) cold damage on a failed save, or half as much damage on a successful one.