I can understand that you're scared of spoiling your story... but you really need to give the audience something with your blurb. You can at least hint at the stakes of your story, like "If he doesn't earn a billion dollars in one year, he'll lose everything!" or "he'll succumb to a terrible curse!" or "a fate beyond death awaits him!"
There really need to be some hints at stakes or the task he's given being legitimately difficult, because "become a tycoon" doesn't sound like a hard thing for the son of a billionaire gifted with super-intelligence to do... unless there's a strict time limit, or an antagonist trying to stop him, or... I dunno, he's marooned in the middle of nowhere with only his clothes or something as a test.
Also avoid using made up words in your blurb without explaining at least their vague meaning. You can't put "regenius" in your title and then when somebody asks "so what is it about?" you just say "It's about a regenius", I don't know what a "regenius" is; it's not a real word! Explain what a "regenius" is, like: "He's reborn as a regenius: gifted at every skill from birth!" (Or something, I have no idea what a regenius is and how it's different from being a genius and if as an English speaker I had to guess the meaning, since "re" implies something going back or repeating, I'd assume a "regenius" was somebody who'd stopped being a genius and become one again...).
Basically, when advertising a story, it's best not to just dump the basic concept and run. Set up:
"Who is the protagonist and what's interesting about them"
"What are their problems or challenges?"
"What sort of bad things might happen if they can't overcome it?"
The thing about bad spoilers that people don't like, is that they're generally not what the scenario is, they're how the protagonist solves it and what the outcome is. It's not a bad spoiler to tell the reader what scenario the protagonist gets into, or what looming bad thing might happen if the protagonist fails, it's a spoiler to tell them whether or not the bad thing happens.
For example, you can't sell the movie "A Perfect Storm" as "Some people go out on a boat. Something happens, but I can't tell you what because it's a spoiler! 
" It has to be "Some people go out on a boat and get caught in a massive super-storm; will they survive!?" because the spoiler is "Do they survive?"
I hope this helps you craft more appealing ways to describe and promote your work!
