S07E17: The Return of Darrin the Bold

Endora and Serena give Darrin powers unknowingly when Serena goes back in time to the 14th century where Darrin the Bold reigns. She has altered the future of Darrin when she puts a spell on Darrin the Bold. In the present, Darrin starts wishing for stuff and he gets it. Samantha finds out about Serena's plan, goes back to the time of Darrin the Bold, and takes off the spell.