Donovan wasn't wholly ignorant of the meaning of the runes nor the glowing circle, although it was the first time a mortal had ever attempted to confine him and he didn't dare try to step out of it. It was a strange feeling, the hum of magic. A reminder that he was dealing with Fate's chosen, blessed with powers that no other mortal could wield. But he wasn't afraid, there was little the cleric could do to actually harm him. Probably wouldn't once this misunderstanding got cleared up.
He hated having to explain himself, but he supposed he was impressed.
"Death," he introduced himself with a short bow, one adopted from a very different culture and time that indicated perhaps he too had been human once, although it was long faded from memory. It was very rare occasion for him to have a proper introduction, had no formal titles to give. "Shepherd of the spirits," he decided, thought it sounded sufficiently important. "Or just Donovan," because he was rather casual about things. Everyone knew him by Death, even if they'd never met until the end, but he reserved his name for those few who could actually see him.
The unattended spirit quietly swayed in place near the bed, probably wouldn't run off anywhere quite yet. Those who died peacefully rarely had too much energy to cause any problem.