I haven't watched the Jojo anime adaptation or know much about the series but I do know Phantom Blood is considered one of the weakest parts of the franchise and I can understand why. The main antagonist is... not the most complex guy around and beyond his rivalry with Jojo I didn't understand why he wanted to do anything, there was no motivation for his actions. He was funny though, iconic character in his own way, commits some of the most vile acts I've seen in a manga actually if you like dogs or babies be warned.

The bigger problems come in with Jojo himself, he is worse than the Dio and I often found myself rooting for the villain just because of how boring Jojo is. His love interest is the worst of all, she lacks any personality whatsoever beyond being in love with the hero. Otherwise I enjoyed the character designed and the art in general has a good aesthetic. It's a fun manga in that campy horror sort of way and I'm interested in seeing where the series will go on from here and the series isn't totally predictable, the series isn't afraid of killing characters off unlike many modern shounen and a few of the story events took me by surprise.

tl;dr it's Fist of the North Star meets Bram Stoker's Dracula.