Scorpion King 2: Rise of a Warrior [is] the prequel to a spin-off that was itself a prequel to a sequel.
If your biggest star is a mixed martial arts champion and you bother to work in a training scene early on where he's shown using moves like a guillotine choke and a cross armbreaker, why on earth when it comes time for the only real one-on-one battle with the warrior hero do you decide to deny audiences a fight between the two in favor of having the legitimate shoot fighting champion transform into a giant invisible scorpion? Yes; a giant invisible scorpion! I realize fight scenes take time to choreograph and CGI is expensive but geez… AN INVISIBLE SCORPION? [source]