This got me thinking in the other direction.. If I were a very determined, ultimate Bond villain* who set out to destroy the whole universe, what are my option

This got me thinking in the other direction.. If I were a very determined, ultimate Bond villain* who set out to destroy the whole universe, what are my options? How bad can I fuck it up for all ? Back-to-back mega nuclear explosions occurring simultaneously on all planets within reach? Could that start chain reactions around our galaxy that'd bring it all down? What else? * Funnily enough, I just started reading 'From Russia with Love' whose first few chapters deal with the unusually vicious nature of our henchman.