Achilles was somewhat smug and overconfident because he was invulnerable, he at one point trapped a missile Robot Junior launched with his mouth and returned the favor.
Achilles mainly uses a sword in combat bolts of heat energy at enemies aside from being used as a close combat weapon. The faces on its wrists can release flames as well as energy beams. The "rings" in his fingers can release lasers. It can also release bats from its left shoulder that allow it to distract enemies.
Achilles is a humanoid Warrior Beast adorned in unique body armor covering him from head to toe. It has a black chest plate with a light green outline, arm bands with open mouthed faces, the left shoulder has armor with a face on it, the right shoulder has a red hole on it, the torso has red scale armor, a light blue belt with a black outline and its purple real face on it. On the lower body, it wears a brown skirt with a green outline, and limbs colored dark blue. Its head wears a helmet with bat wings on the side of its head and on the forehead emblem while the lower face is covered by a grilled mask. It has glowing yellow eyes. [Source: wikia]
You can download this papercraft template here: Great Mazinger - Warrior Beast Achilles Free Robot Paper Model Download