Stain - Mentor and Student

Appearance

Chizome's general appearance is that of a tall man with a muscular build. He has messy black hair, a long pointed tongue and a flat face with no visible nose, due to cutting it off.

As Stain, he wears a combative outfit armed with sharp-bladed weapons, a long torn scarf and a bandana around his neck and eyes. He also wears bandages around his arms and boots with spikes on the toes.

As Stendhal, his hair was much longer and kept in a straightened ponytail and wore a mask that covered the entirety of his face. His overall outfit was heavily armed with combative armor.

Personality

Chizome is a very cold-hearted, methodical, and ruthless man. When he was in high school, he noticed how some students were applying to become heroes simply for income and fame. Disgusted by those ideals, he created an ideology of building a new world filled with true heroes. At first, he tried to spread word through communication, but when no one listened to him, his only other method was concentrated bloodshed, killing all the heroes he deems as "fakes". Better explanation, Stain targets the likes of anti-heroes (heroes with bad qualities.)

Despite his unforgiving nature, Stain has come to respect others. The most notable example is All Might, whom Stain believes to be not only a true hero, but the only real hero to exist in the world. His admiration for All Might runs so deep that he's the only one he's willing to let kill him. However, Stain has also shown respect to others who are strong and bravely willing to fight to save someone's life like Izuku Midoriya, to the extent his respect for Midoriya allowed him to spare his life.

However, he can be utterly disgusted by heroes who are out to stop him for their own selfish purposes and has no compunction about killing them, like Tenya Iida, whose only desire was revenge against him for nearly murdering his brother. While Stain despises heroes who are out for fame and money, he also dislikes villains who are out for unnecessary violence and bloodshed, such as Tomura Shigaraki.

As Stendhal, he was a ruthless vigilante who had no problem with killing criminals and believed those who wielded power without conviction deserved death. That being said, he also had no problem with allying himself with villains like Kuin Hachisuka if it worked in his favor. He also appeared to have a split personality, treating his vigilante and civilian personas as two different entities. After his confrontation with Knuckleduster, however, Stendhal changed his beliefs and came to believe that "fake heroes" were the root of society's problems, which led to him becoming the notorious hero killer he is known as now.

Powers and Abilities

Bloodcurdle: Stain's Quirk allows him to paralyze and immobilize his opponent by ingesting samples of their blood. Depending on the person's blood type, the amount of time for a victim to be paralyzed varies, with Type B being the longest duration. Nonetheless, the maximum duration for someone to be paralyzed is said to be for only 8 minutes. In his last moments, it was stolen by All For One, thus dying Quirkless.

Immense Speed & Reflexes: Stain has shown to be quite agile and evasive as he was capable of avoiding Iida's attacks with ease. He has also shown to have great reaction time, as he was able to evade and kill many heroes in the blink of an eye

Enhanced Strength: Stain has shown an enhanced degree of physical strength when slicing through ice walls with one strike.

Immense Endurance: Stain seems to have a high pain tolerance, as shown when taking a full punch of Midoriya's 5% Detroit Smash and a full kick from Iida's Recipro Extend. He was also able to tank Todoroki's fire, with only scratches left on him. He was also shown to be standing still, even after having his lungs being pierced and losing consciousness.

Highly Perceptive Combatant: Stain is a very cunning combatant. He has shown to have both creativity and mastery over his fighting style, capable of fighting his opponents from close and long ranges through a mixture of misdirection, aggression and prediction. He also uses the environments around him to give him advantages.

Intimidation/Fear Inducement: As an infamous killer and villain, Stain proves to be very frightening and holds an unparalleled bloodlust towards the heroes he deems as "fake" which he unleashed after nearly escaping his capture. His killing intent was released in a terrifying wave, which struck a paralysing fear into everyone present including two veteran and powerful pro heroes, Endeavor and Gran Torino respectively.