Şehrin görkemli silueti sabah sisle mistik bir havaya bürünüyor.

görkemli is an adjective meaning magnificent or splendid. It’s built from the noun görkem (splendor) plus the adjectival suffix -li.
Example: görkemli bir bina = “a magnificent building.”

• sabah acts as a time adverb: “in the morning.”
• sisle = sis (“fog”) + instrumental suffix -le (= “with”).
  So sabah sisle means “in the morning, with fog.”

• -le is the instrumental/comitative case meaning “with.”
• sisde (locative) would mean “in the fog,” which doesn’t convey “with fog.”
• sisli (adjective) would mean “foggy,” describing something as foggy.
  Here we need to express “with fog,” so sisle is correct.

• mistik = “mystical” (loanword)
• bir = “a/an”
• hava = “air” or “atmosphere”
• The dative suffix -ya is required by the verb bürünmek (to be enveloped in).
  Thus mistik bir havaya = “into a mystical atmosphere.”

• The base verb is bürünmek = “to be clothed in” / “to become enveloped in.”
• Drop -mek, get the stem bürün-, add the present-continuous suffix -üyor.
  So bürünüyor = “(it) is being enveloped” / “(it) becomes clothed in.”
  This verb emphasizes a gradual, immersive transformation.

Turkish word order is flexible, but the neutral/orderly pattern is:
Subject → Time/Manner → Verb.
You could move adverbials around (e.g., mistik bir havaya sabah sisle bürünüyor), and it remains intelligible, but it sounds marked and less natural than the original order.