The thing that lingers for me is how Granbell and Rimuru are basically chasing the same goal with completely different tools. One got Raphael handing him the peaceful answer and the other only had his own stubborn hope for centuries. Granbell naming his skill Sariel Lord of Hope right before Luminas cut him down felt like the show admitting he was never the villain just the version of Rimuru who ran out of options. His final words being a compliment to the woman who killed him says everything about who he actually was