Giddianhi was a master of sarcasm. He notes that he has a very large army, one that has been proved in battle, and which has an “unconquerable spirit.” Even worse, they have an “everlasting hatred” for the Nephites. They are ready, they are even anxious, to be sent to destroy the Nephites.
Giddianhi writes that he feels for the Nephites and is personally holding off this army that is straining for the command to go to battle. Only out of such kindness is Giddianhi writing. It is an attempt at intimidation, but one that does not appear to care whether or not the Nephites are intimidated. Giddianhi clearly believes that he can conquer the Nephites.