Some time before the start of the game, Strong Heart went on an expedition to the Bugmuck to search for rare alchemy ingredients. However, he ran afoul of Thraxx and was imprisoned in the bug's webbing. When the Hero arrived in Prehistoria, Elizabeth sent him to find Strong Heart. The hero destroyed Thraxx and freed Strong Heart, who returned to his home in the Southern Jungle.
In the ending, Strong Heart is overseeing the village with Elizabeth as Evermore is wracked with earthquakes, and the hero comes to take her home. Strong Heart tells her she must go, but that she will always have a home with them. With Elizabeth gone, Strong Heart becomes the new leader of the village.
Strong Heart gives the player 10 Wax and 10 Oil upon being rescued from Thraxx. When visited in his hut, he gives the player the Cure formula. When revisiting after completing Gothica, he gives them the upgraded Miracle Cure.
Strong Heart sells alchemy ingredients to the player. His stock changes when the player returns to Prehistoria after finishing Gothica. He is notably the only permanent alchemist in the game to stock Vinegar; the only other alchemist to sell it, Madronius, is inaccessible after defeating Aegis.
- If the player talks to Strong Heart as the Dog, gives them a free Leather Collar. When revisiting Prehistoria, doing the same has him give a Spot's Collar.
- Strong Heart has a daughter and brother living in the village; his brother is the merchant who sells alchemy ingredients.
- Strong Heart implies he has travelled to Nobilia, as he is in good standing with an alchemist guild there.