Has an AFL game ever ended 118-21?
Exactly once. On July 9, 1955, Melbourne beat St Kilda 118-21, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 118-21 in league history.
That makes 118-21 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 119-21 has happened never and 118-22 has happened never.