WARNING: The following contains spoilers for Conan the Barbarian #18 by Jim Zub, Luca Pizzari, Israel Silva, and VC's Travis Lanham, on sale now.
Conan the Barbarian is famed for his incredible strength, both in terms of his physical prowess and his indomitable strength of will. It is this raw power that has allowed him to overcome any enemy, whether fighting other people, wild beasts, or ancient demons.
While Conan is famously one of the most accomplished swordsmen in comics, the very sword in Conan's hand is the thing that defeats him in Conan the Barbarian #18.
After having acquired a katana known as the Tooth of the Nightstar, Conan sets off for the distant land of Khitai to return the weapon to its rightful owner, Maltus-Rai. An ancient curse has been placed upon the blade and soon the barbarian is overcome by hallucinations that threaten his grasp of reality. A band of warriors attacks him in a mountain pass and he is forced to take up the Tooth of the Nightstar to defend himself.
This is the setup at the start of Conan the Barbarian #18, which opens with the titular hero reflecting on all the past battles he has survived as he wields the cursed sword against encircling foes. The blade blazes with a fiery orange light in his hand while his eyes glow with a red, but the weapon gives him the strength to defeat his attackers. Only once they are slain does Conan look upon his handiwork, at which point his vision clears and he finds himself standing in a tent village, having just murdered all of the innocent unarmed villagers.
The horror of the revelation shocks him, and once again, the sword seizes control. Speaking straight into his mind, the Tooth of the Nightstar reveals its bloody history from the day it was forged through the years of battle and betrayal in its wielders' hands. The sword repeatedly calls Conan a vessel, a term that offends the barbarian. It tempts him with promises of wealth and women, if he willingly agrees to wield it, giving the blade the blood it craves in exchange for the strength to take whatever he wants for himself. Still, Conan refuses. To punish this defiance, the sword takes control of his arms and forces him to raise its glowing edge to his own throat. He can agree to be a vessel to the cursed weapon or else it will kill him.
With a final effort of will, Conan manages to throw off its control over him. Exhausted and disoriented, he lets the katana fall at his feet. A moment later, he is attacked by Khitai warriors, but by this point, Conan is so weak from his struggle with the Tooth of the Nightstar that he is captured without even putting up a fight.