Artaith, the Broken Shield

Transformed Monster. When Artaith transforms into this statblock, she regains 100 hit points from her current hit points when she transforms. Artaith can not transform back into her non transformed form.

Gwyneria's Blessing. Artaith's attacks count as magical for the purpose of overcoming resistance and immunity to nonmagical damage. Additionally, she counts as both a draconic and monstrous creature for the sake of spells and abilities.

Cruelty Knows No Bounds. Artaith has advantage on attack rolls against all creatures that are frightened, or have less than half their remaining hit points and are still conscious.

Regeneration. Artaith regains 10 hit points at the start of each of her turns. If Artaith takes any fire damage since the start of her last turn, the regeneration trait does not function.

Human Weaponry. Artaith can use a grappled, conscious character as a weapon in place of her Rock attacks. Any attacks that hit have its damage divided in half between the target of the attack and the grappled, conscious character. If Artaith must throw a grappled creature at by the end of her turn, so she cannot use Ruthlessness is Mercy after her third attack in a turn. She does not suffer disadvantage on her ranged attacks while throwing a grappled creature if that grappled creature is the only hostile creature within five feet of her. If a creature is knocked unconscious by the damage being split by Human Weaponry, Artaith must immediately use her next attack to throw them, and they do not take damage from the attack. The target of that attack takes the full damage of the attack as normal.

Unstoppable Force. Artaith's movement does not provoke attacks of opportunity on the turn she transforms or if she is at full health.

Multiattack. Artaith makes up to three attacks on each of her turns, using any combination of Unarmed Strike and Rock.

Unarmed Strike. Melee Weapon Attack: +13 to hit, reach 5 ft., 1 target. Hit:  16 (2d8 + 7) bludgeoning damage and 11 (2d10) cold damage.

Rock. Melee or Ranged Weapon Attack: +13 to hit, reach 5 ft. or range 60/120 ft., one target. Hit:  25 (4d8 + 7) bludgeoning damage.

Ruthlessness is Mercy. When Artaith hits a conscious creature with an Unarmed Strike, she may use a bonus action to grapple the creature. 

Gwyneria's Fury (3/day). Artaith releases a surge of icy energy, in an attempt to freeze her enemies ambition. Each creature within 30 feet of her must succeed on a DC 15 wisdom saving throw or become frightened of her 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.

Artaith 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. Artaith regains spent legendary actions at the start of her turn.

Fight (uses 1 action). Artaith can make an unarmed strike or rock attack.

Flight (uses 1 action). Artiath can move up to her move speed. If she is moving towards a creature with less than half of their remaining hit points, she can move up to twice her move speed instead.