Orn (Slumbering in ancient Lordrian)
-et ( Which is ancient Draconian power word, And means 'Bane'
-shin ( Real Name of Slumbering Dragon which means Reptilian)
-e ( The word "e" stands not alone but with the word "shyan" which comes from "Shin-e" which means The suns firstborn and its the true name of Nameless King God of Storm).
And the meaning of Ornstein is Shin (Slumbering Dragon) Shyan's Bane.
Which betrays the real origin and existence of Ornstein.
All dragons can take human form, because are Godly Creatures and here Shin took the form of Ornstein because he couldn't slay as a dragon the God Nameless King the slayer and tamer of all dragons, but he could deceive him and betray him the way you already know from ds1.
I am a lore-keeper and in depth professor of history and word examination, and i felt the need to explain you the truth.