Lol, I had such an epic final run!
I did a playthrough trying to build only one full team of five. The final run ended up being one of each type, with 2 S-classes, 2 A-classes, and one runt B-class wildling. At the very end, as most of them were running out of life and mana, the healer died! Everyone else ran almost directly except for the B-class runt who was all "I will avenge you!" - while still just about out of life and mana.
I was all 'oh f*ck' in my mind, assuming I would have to build up a new wildling AGAIN, but before I knew it, she had cut down the demon! The runt was no runt, the runt was the MC! Tristram is saved!