I love the way he's reading this
Why zaldrīzī is not a plural?
"Zaldrīzī" on its own can be both singular and plural, but the possessive in this case does indicate whether it's singular or plural. "Ñuhi" is singular, "Ñuhī" would be plural.
How does 'they' come into this sentence ? Why isnt is my dragon is chained or in chains?
"Ñuhi zaldrīzī" is in the accusative, so it can't be the subject of the sentence. And so, based on the verb, the subject has to be third person plural - they.