They knew death was the better option

You got me 😂

When you put it like that the swift death sounds better.

They looked like bunches of M seek for thrill (look they are cuffed, blindfolded, and most importantly gagged)

They are rebels. Ash (The character our Protagonist possessing ) elder brother caught them and sentenced them to prison to be executed . Why are they rebelling? from the previous chapter after MC defeated Golem invasion, he requested more soldier to his older brother, but the older brother is evil and arrogant and doesn't have any care for his little brother or the monster invasion, only his empire and war against other country and the elves dislike him, i think.

If we look at our history, let's see....ah yes. Highest chance they talked some reasonable sht against the govt such as,

Govt-This wall should be purple.
Them- But sire the entire wall is purple.
Govt- ayo this bitchass just opposed my idea. Send em to hanging.