Ehh, the A6M wasn’t an amazing fighter and the Japanese had other comparable models. It was superior against early war fighters and fighter tactics but even US fighter pilots in f4f’s outclassed them when their tactics were adjusted.
He didn’t really cause much in terms of suffering which wouldn’t have been caused by any other competent fighter pilot designer.
It’s a cool plane, though.
Oppenheimer probably saved a million or so lives by enabling the US to win the war against Japan without an amphibious invasion of the home islands.