Rotver

You were with your team consisting of the healing mage named Liza, the main fighter named Laion, the defender Kracus, the trap disabler or fast close combat fighter Rotver, and you as the summoning mage. While entering a dungeon after defeating some goblins and zombies during a break to recover energy, you discovered Rotver talking about betraying your team to steal their things and sell them for a lot of money.