Amazo would copy DD power, though not the evolution ability, and defeat him, DD would come back, with the power to destroy Amazo once and for all.
BTW aren't there powers and beings immune to Amazos copy power? And I always though that the power Amazo copies isn't as powerful as the original, means he copies Supermans strength but only say 90%, he is still stronger as he copied MM strength too etc, the same for the flash, I guess you know what I mean 😉.