The image of a gladiator standing tall on top of a charging rhino flying through the Roman Colosseum became one of the shining moments of the “Gladiator II” trailer — but the idea actually took more than two decades to complete.

Ridley Scott’s “Gladiator II” is full of a memorable action scenes, from a bloody showdown featuring CGI baboons to Paul Mescal outsmarting a charging rhino in the Roman Colosseum. But one sequence that is sure to leave audiences with the most questions is a rather insane set piece in which the Colosseum is filled with