What do you mean by 'powerful'? I heard that Tang Dynasty(https://www.travelchinaguide.com/intro/history/tang/) is also considered as the one of the most powerful times in Chinese History(https://www.travelchinaguide.com/intro/history/).

It is not right to say Ming emperors more powerful than Tang or Song rulers. There are powerful or weaker rulers in every dynasty. Except the first and empror and Emperor Yongle, most are weak and talentless. If you mean cruel by powerful, perhaps yes. Ming has more brutal punishments.