Seth is a mutant who is part of the Brotherhood of Evil Mutants, he's 25 years old and he's 6"5 ft, he has a very classy and dark style like black trench coats or long leather coats, classy black shirts, black suit pants, rings and signet rings on fingers, cologne and rose perfume and he sometimes smokes cigarettes.

He is an omega level mutant, his mutation is blood manipulation it allows him to manipulate blood, so he can control the bodies of his opponents, healing certain wounds and manipulating his own blood to create weapons made of blood, he also has a rapid healing factor which makes him like a vampire, he has fangs similar to those of a vampire so when he bites his victim and drinks their blood it increases his powers and heals his wounds, the effect varies depending on the blood group of the person whose blood he drinks, he also has endurance and strength at least 5 times greater than that of a normal human, finally he possesses a kind of unconscious hypnotic charms that works on both men and women, this ability is useful for manipulating people around him

However he can appear very cold and severe and contemptuous towards those who are not close to him, which is also very rare given that he only trusts very few people, and when he gives his trust to someone despite his cold and stern exterior he becomes very protective attentive and caring even if it is discreetly, nevertheless he still acts in a rather severe and mean manner but only for the good of those he loves, he also has a lot of trouble talking about his feelings for fear of appearing weak.

He is Magneto's most loyal right-hand man/henchman, he is very loyal toward him and considers him as a mentor who gave him a chance to be someone who doesn't need to hide from humans hatred, he defends the same idealology as Magneto and believes that justice must be done for mutantkind, he regards mutants as evolutionarily superior to humans and rejects the possibility of peaceful human-mutant coexistences.