Fritz Haber is such a tragic character. Saved the world from hunger by inventing the process for ammonium fertilizer, helped to kill thousands by being a central figure in building up German chemical weapons for WWI, tried to extract gold from seawater to pay Germany's WWI debt but of course failed. He was a huge patriot, but being a Jew, he had to go on exile to England, where he died.
A nod to the graciousness of England, not just for accepting him as a refugee, but for those former military enemies and chemical warfare competitors, who actively helped him by offering a position at Cambridge:
[1] https://en.wikipedia.org/wiki/Fritz_Haber