The Fantastic Greatsword is a melee-type weapon that can be obtained in the Frontier. This weapon can be obtained by defeating the Fantastic Dragon or the Pygmy Dragon at A Frontier of Dragons or by purchasing it from the Otherworldly Weaponsmith in The Town of Right and Wrong. This weapon is considered to be a rare drop from the Fantastic Dragon, making it a difficult item to get for those who claim they are unlucky.
The player can use its special attack, known as the Fantastic Beam. It shares similar attack features of the Fantastic Dragon's beam attack.
In appearance, it's a legendary glowing blade materialized from the pure will of the dragons, according to its description. Yellow seems to be the main color of the greatsword, alongside with shades of gray, blue, brown, and red.