>>76955484That's an entirely different scenario though. We have this character we've seen grow up, who is suddenly an alien that is fighting for friend's lives on a foreign world. He is told, repeatedly, the legend passed down by his true kin, about an amazing strength that has been lost with time, that may just be a myth. Then, when he experiences great turmoil, he is able to transfer this energy into strength, transforming him into the legendary Super Saiyan.
It was an established mythos in the world, that we weren't even sure was real. Nobody expected something like that could happen. And from a story perspective, it's also fulfilling that he is able to defeat the being that executed the rest of his people, by using his own's people's legend. And it's our beloved hero taking another step up the ladder.
With Dennis becoming a Vampire, it's just cliche. We expect him to become one. Then it's 'Oh no! The bad guy is here! Now I better do the thing that everyone expects so I can save the day with no explanation, other than a hand waved fear tactic' There's nothing fulfilling about it. But that may be because of the bad guy just showing up out of no where to be the bad guy, rather than it just being Dennis' fault.