With the extra trolls, and the army joining their flank, the fight turned into a steady advance toward the barrier, which was still steadily deploying more monsters.
Then, the mages made a fatal mistake.
Whatever spell they were using to find monsters had gathered them two hundred swamp trolls, short and long-armed monsters who typically covered themselves in moss, mud, and swamp grass to keep their skin from drying out in the sun.
They left the barrier like everything else, but when they got near the front, they just turned around and started attacking the monsters around them.
Trolls were challenging to control, and once they understood that all the other Trolls were fighting in the other direction, they just turned around and changed teams.
They didn't have a proper swamp around here for them to live in, but they might be fine in the forest if they survived this battle.
The troll village could get them settled if they needed.
