Though deceased, he is very important to the game's story as he discovered (or rather, rediscovered) the Secret of Evolution, which the forces of Nadiria sought to exploit. After his discovery Balzack murdered him, orphaning his daughters and causing them to begin a vendetta against Balazack that ultimately led to them following their destiny in joining the Hero of Dragon Quest IV on his/her quest.
His other apprentice, Oojam briefly aided the sisters in getting revenge in chapter 4.
Not much is stated about Mahabala as a person aside from that he was a dedicated father and beloved by the villagers of Aubout du Monde, but his alchemical expertise is well documented. Considered a true master of rasatantra alchemy, Mahabala was responsible for the creation of creation of the levitating platforms found in his hidden laboratory Gupta Gupha, the Night light, the Magic key, and the Sphere of Silence, among other marvelous developments. His true claim to fame was the (re)discovery of the secret of evolution, which had been lost to the ages.