'Zat so?
Were there any sequels to Enter the Dragon, Bloodsport, or The Quest?
The answer's No.
Why is that you ask?
Because it is hard to sustain an entire film franchise based on a tournament setting.
A Soul Calibur film would not be limited by a tournament setting. You can adapt it into a grand epic tale that could still remain true to the original source material. And you could have Link debut in a post-credit stinger.