acronyms take a large combination of words and make them into combination of letters (usually using the first letter of each word)
SWAT is often used to refer Special Weapons And Tactics police, so here the long word is shortened with combination of few letters (each letter is first letter of the word)
It could be said that both were ready to die for the cause, they knew that this was a possibility so that why they were brave and determined. it might also reflect that both acted for revenge. what is more, they are ready to kill Beowulf is ready to kill the monster and the monster is ready to kill him and hurt his people.
