Board Thread:Manga Discussion/@comment-33204772-20190109170729/@comment-37422009-20190120234946

Depends what you mean by most powerful. Assuming we're going by their strongest forms, Pucci with MiH can have the largest effect on the world if needed. However, Valentine with both D4C and Love Train still has more powerful defensive capabilites, being nearly invincible and being able to replace himself as he dies. In 1v1 combat MiH can beat any of them by resetting the world and killing them in the "past". I'd say ultimate Kars likely has the most versatile abilities though, as he can change into any life he wants for any purpose, while the other villians abilities are tailored to do generally just a few things. Weakest is Phantom Blood Dio if he counts, if not then Kira.

EDIT: unless we're including all villians, then the weakest is the superfly user; he actually doesn't have any abilities of his own (since his stand responds to him and others exactly the same way) aside from some hand calluses.