The Hunters gang were all being attacked at once.
In Pillow's Grove City, Hank was the only one working for this branch of the gang. There were other fighters in the city with him, but due to his power, only he could fight.
Anyone else fighting would cause problems that they couldn't deal with.
The other fighters instead set up a perimeter around the small underground location so that they caught every gang member that tried to escape.
Hank went into the underground alone with nothing but his weapons in hand and two pouches on his jacket. As he got close to where the gang members would be, he pulled out one of the pouched which was full of blood.
As soon as it was out, he hesitated for a second before tearing the pouch with his teeth and drinking all the blood inside of it.