Looking for a horror manga I read some years ago
This is Lychee Light Club. On the cover you can see the black star, the symbol you mentioned , on the leader's glove. He was indeed told by a fortune teller that he would be more evil than Hitler - and he takes pride in it.



The Frankenstein monster you're thinking of is Litchi. He's powered by lychee fruits. He was created so that he could capture beautiful girls for the club. He discovers love from one of his captive females and betrays the club whilst defending her.



The anime is significantly less dark than the manga and the characters are in a chibi art style