Kars is the leader of the Pillar Men, and the designer of the Stone Mask. His goal is to evolve further to become immune to the sun's rays and thus he seeks the Red Stone of Aja to empower his Masks, battling the Hamon users for its possession. He is ranked 1st out of all the Pillar Men.
Kars is intelligent, ruthless, and single-minded in his dedication to obtaining the Red Stone of Aja. He was stated to have been a genius among the Pillar Men, having been the original creator of the Stone Mask