This is very much a Castlevania reference. In the Castlevania universe, every time a maid shows up (usually a vampire maid), they're ninjas. Lord only know why it is that Dracula decided he needs servants trained in the arts of Shotokan, but he does.
He's an eccentric old vampire, and really, who are we to judge?
In other matters, remember that Darkmoon has never been to the future. Vehicles aren't at all common, so there's no reason to assume he'd even have any understanding of what a Technodrome is.
 
    

When evil spreads across the land, and darkness rises and the monsters roam. When the creatures of the night make beautiful music, and the things that go bump in the night go bump with greater enthusiasm. When the world is in peril and is in need of a hero...

These guys are, sadly, the best the world can hope for. These are the adventures of the heroes of CVRPG. They mean well, they try hard, and occasionally they do the impossible...

They actually do something heroic.