Fantasticness is a captivating concept that embodies awe-inspiring qualities. Though there may not be direct synonyms, several words can aptly describe its essence. First is incredibility, denoting the ability to elicit amazement and disbelief. Another term is extraordinariness, emphasizing the exceptional and remarkable nature of something. Magnificence encompasses grandeur and splendor, portraying an overwhelming sense of beauty or brilliance. Similarly, sublimity signifies the lofty and transcendent aspect of a subject. Lastly, we have wondrousness, illustrating something that causes wonder and admiration. While none can perfectly capture the unique brilliance of fantasticness, these synonyms provide a glimpse into its magical and mesmerizing nature.