Marvin's move was really too fast, startling everyone.
The nobles and soldiers from River Shore City originally thought that Marvin was a sort of gigolo that Madeline wanted to keep around.
When Marvin got on Madeline's carriage, they looked at him in contempt.
When the Magic Holy Grail appeared, it made them realize that the City Lord had searched out that noble from the countryside for this reason.
In fact, news in River Shore City spread pretty fast, and Marvin's display in the Battle of the Holy Grail had already spread through the East Coast.
But the main characters from the previous Battle of the Holy Grail were always Wizards, so the rumors about Marvin were dismissed by most people as him deliberately showing off.
They preferred to believe that Marvin's younger brother Wayne had an outstanding performance, winning the brothers the supreme honor of getting the Holy Grail.