Mastertronic Added Dimension, 1987
In previous episodes (Spellbound and Knight Tyme) Magic Knight rescues his friend and tutor Gimbal the Wizard from a self inflicted White Out spell, and then finds himself catapulted into the 25th Century aboard the starship USS Pisces. Having aquired a secondhand time-machine from the Tyme guardians, Magic Knight finally reaches his own time and planet - but with a slight problem; Whilst travelling back, a serious malfunction occured with the secondhand time machine, and now, horror of horrors, there are two Magic Knights!
The other Magic Knight is a real nasty piece of work. He calls himself the "Off White Knight", but locally he is known as the Stormbringer because of his powerful and dangerous Storm Cloud, which he is planning to use to destroy Magic Knight.
In your role as Magic Knight, you realise that you cannot kill Stormbringer, because if you do, you will destroy yourself in the process, the only way for you to become your old self again is to merge with him. Good Luck, Magic Knight!