I found these mystical symbols.
What do they mean?
The challenge's headline photo of an island, along with the bolded word myst in the challenge hint, led me on a Google search for a cipher from the 1993 game Myst. I found a translation chart containing symbols matching those in the challenge image, but I had no luck producing a translation that consisted of valid ASCII values.
Further research led me to an article that explains the D'ni counting system is base-25 and provides a detailed explanation on translating the symbols. I additionally found an on-line D'ni number converter which I used while completing the challenge. For example, the first block of symbols converted to the value 83.
Once I had all the block values, 83 49 114 114 117 122, I used the From Decimal operation on CyberChef to convert to ASCII characters to produce the string, S1rruz.
The accepted flag was,