Copper Shinryu

Angel's Sight. Magical darkness doesn't impede The Shinryu's darkvision. 

Magic Resistance. The Shinryu has advantage on saving throws against spells and other magical effects. 

Angelic Weapons. The Shinryu's weapon attacks are magical. 

Glowing Stealth. While in light with no shadows, the Shinryu can take the Hide action as a bonus action.

Change Shape. The humanoid magically polymorphs into a shining, copper dragonoid that is a size large or back into its true form. It reverts to its true form if it dies. The Shinryu chooses whether its equipment falls to the ground in its space, merges into your new form, or is worn by it. Worn equipment functions as normal, but the DM decides whether it is practical for the new form to wear a piece of equipment, based on the creature’s shape and size. Its equipment doesn’t change size or shape to match the new form, and any equipment that the new form can’t wear must either fall to the ground or merge with it. Equipment that merges with the form has no effect until the Shinryu leaves the form.

Multiattack. The Shinryu makes three attacks: two with its rapier and one with its bite.