Trillion: God of Destruction is a strategy RPG where you must train Overlords to fight Trillion a god of destruction that is eating the underworld. Trillion sleeps after eating part of the underworld giving you a chance to train. You will have 6 attempts at stopping Trillion before the underworld is gone. You choose from one of three Overlords to train at the start. You have a set amount of time to train and prepare for the fight against trillion to defend the underworld. You can train stats, learn skills, go into a dungeon to gather items, strengthen weapons, and rest to get rid of fatigue. You can also interact with the Overlord to raise affection points, raise affection to a certain level and events related to the Overlord will occur. Affection points are also used in the battle against Trillion where they act as a buffer for your health and mana. As long as you still have affection points in the battle you will also have the option to retreat from the battle, giving up a section of the underworld for more time to train. If the Overlords health reaches 0 they will be able to activate a final death skill that could deal massive damage, seal one of Trillion's attacks, or stop Trillion's advance for a longer training period. The Overlords items, equipment, and seals will be passed on to the next Overlord you train along with a portion experience.

"The Underworld---The denizens of the Underworld lived a free life amid conflict against the Heavens. There arrived a mysterious threat, a giant evil creature. This is the "God of Destruction." The eater of worlds... The Underworld is at a loss against its tremendous power. Even the mighty Great Overlord Zeabolos falls against its greatness. Near the brink of death, Zeabolos hears a mysterious voice... "Are you willing to offer your very soul to defeat it?" The moment Zeabolos agreed, he revived into a patch worked body. And thus, Zeabolos rises once again with the mysterious girl, Faust, at his side, to face Trillion. Train the Overlords as candidates to be the next Great Overlord, and to defeat the God of Destruction!"