Laconic phrase. What is a Laconic phrase? A laconic phrase or laconism is a concise or terse, especially a blunt and elliptical rejoinder
It is named after Laconia, the region of Greece whose ancient inhabitants had a reputation for verbal austerity and were famous for their blunt and often pithy remarks
It is used for efficiency, for emphasis, for philosophical reason or to deflate a pompous interlocutor.
And that is what the answer of Death Monarch akin to. When the envoy arrives at the Island of Peace and present the letter, they were in a large hall. Everyone was waiting.
When they saw that all of their envoy were unharmed they felt relaxed. It means that Death Monarch was not angry.
The envoys look at their leaders and finally understood why they were sent.
