The Megachelon is passively tamed by guiding a microbe swarm alongside it while protecting both the turtle and swarm from hostile creatures, without trapping or losing proximity. Once tamed, it serves as a massive mobile building platform with an underwater oxygen bubble, multiple passenger seats, strong defenses, resource-gathering abilities, and passive production of rare plants. When encountering or fighting one, attack from its back near the surface while avoiding its attacks and nearby aggressive aquatic creatures, using powerful elemental damage for greater effectiveness.