Collecting Soldiers

What do I exactly mean by farming footsoldiers?

Let me give you a good idea…

…

"Brother, I'm cold." A guard grumbled.

"So? Your wife told you to wear the wool thingy underneath your armor, but you refused to listen…" His patrol partner replied.

"I would've been sweating like a pig if I did!" He replied with more gusto than he wanted to.

"Calm down, dude…"

Even before they could react, a shadowy figure dashed at them and slashed their necks. Both guards tensed and reached for their throats from where the warm red liquid began slowly spilling. They tried screaming but no sound came, their vocal cords have been ruined.

They couldn't help but think that their assassin was a weak one, for he failed to cut their necks properly.