Lightning Warrior Raidy III

After her adventures in the previous game, Raidy continues her adventures, with the three monsters Fonfon, Tiss and Folles following behind her, upset at having lost their home in the dungeon. They head to the crime-ridden town of Vice, where Raidy hopes to get help from the local Thieves' Guild. When the four are unable to pay for their meal at an inn, they get in big trouble. The only way to pay off the debt and get their weapons back is to enter a dungeon and remove an evil alchemist who's been kidnapping the humans in the town to perform experiments on them...

Once again Raidy must enter a series of mazes and defeat wandering monsters and evil bosses who do naughty things if she loses. But this time there's a new twist: a magical item that allows Raidy to merge with one other individual, allowing the creation of a new being with new strengths that are suitable to take on this new challenge.

[From JAST USA]