Feat[]
“Hrmph.” Ironwood Zhan’s hands summoned a formation flag out of nowhere. He immediately flew backwards, then began running around Ning, surrounded by boundless water and fire, in a circular pattern, while constantly throwing out one flag after another, all of which stabbed deep into the mud.
In but a few seconds, eight formation flags had all been planted, covering an area of a square kilometre. - Desolate Era, Book 3 - Chapter 3
Calc[]
Circular Area = 1 km^2 = 1,000,000 m^2
Radius = SQRT (1,000,000 / π) = 564.189583548 m
Circumference = 564.189583548 * 2 * π = 3544.90770181 m
Time = 3 seconds
Speed = 3544.90770181 / 3 = 1181.6359006 m/s = 3.445 mach
Result[]
Ironwood Zhan's Speed = 3.445 Mach (Supersonic+)