Final answer:
Surah An-Nas is the Quranic Sura mentioned with themes of refuge and Khannas, also noted as the last Sura.
Step-by-step explanation:
The Quranic Sura characterized by themes of refuge and reference to Khannas, as well as being the last Sura, is Surah An-Nas (b). (Figure 13.3.18): illustrates a typical method of demarcating the verses of the Quran with distinctive ornamental elements like the five gold circles at the end of each verse.
The Quranic Sura that matches the given clues of 'Refuge' and 'Khannas' is Surah An-Nas. Surah An-Nas is the last surah of the Quran and it addresses seeking refuge from the whisperings of Satan. It is a short surah that emphasizes seeking the protection of Allah from the evil influences of the world.