Those explosions were a problem. Each time they killed one of the Grimfangs, for some kind of reason, the monsters exploded.
This meant that either they had to attack from a distance, like in Reidar and Lysa's case; be fast enough to get out of range, like in Lena's case; or simply act as a distraction, as in Torren's case.
Torren did the best he could to not kill the monsters and get out when the others dealt the damaging blow, but it wasn't easy. At the same time, Jorik protected the group as best as he could.
As for Reidar, thanks to his summons, he was not in danger, as he remained within Jorik's barrier.
His summons were a mess, though. The blasts kept catching them off guard, so Reidar had to keep bringing them back again and again, which consumed his mana.
