Random Top Times Superheroes Went Bad (30 items)

(#5) Scarlet Witch

After Wanda Maximoff, the Scarlet Witch, had a complete nervous breakdown from the death of her sons, she used chaos magic to cause several random attacks that appeared to come from other enemies which destroyed the Avengers and killed Ant-Man, Vision, and Hawkeye. After the dust settled, she was whisked away by her father, Magneto.
Afterwards, she went into an unstable, catatonic state. Under her brother's persuasion, Wanda created the House of M alternate reality.
(#27) Storm

In Uncanny X-Men Vol 1 #159, Storm is actually bitten and transformed by Dracula and goes on to attack the X-Men.
Yes. The Dracula.
Although she breaks his spell and does not continue her transformation, there is an alternate version of Storm in the Mutant X timeline where she does not break Dracula's spell. She takes the name Bloodstorm (get it?) and is an on again, off again, member of the X-Men and The Six.
(#29) Mary Marvel

After Mary Marvel gains Black Adam's powers, the corruption drives the character to be more violent and act questionably by working with Eclipso and running errands for Darkseid. During Final Crisis, she is actually possessed by the New God, Desaad, and works as one of Darkseid's Female Furies.
After teaming up with Black Adam and joining the evil Black Marvels, the wizard Shazam appears and strips Mary of all of her powers.
(#3) Robin

Jason Todd was always a cranky kid. Being the second Robin, he had to live in the shadow of Dick Grayson and also had a crummy home life before becoming Bruce Wayne's ward. Fans were sick of his attitude and voted to have him killed in Death in the Family.
When Superboy punched reality (we know, bear with us - it's comics), Jason was brought back to life. Ticked off at Batman for not avenging his death, he donned the Red Hood persona and started cleaning up Gotham with a pair of Glocks. Now less murderous, Red Hood is more of an anti-hero and works with Batman in current continuity.
(#6) Spider-Man

During Marvel's Secret Wars story line, Peter Parker got himself a stylish new black costume. It turns out that the costume was actually a living symbiote that, while looking super cool, made Peter a total jerk. With the help of Mr. Fantastic, Parker forcibly removes the costume and is rid of it's negative affect on him.
However, the symbiote later escapes and attaches to Eddie Brock who would become Venom. One could argue that is an even bigger negative effect on Spider-Man's life.
(#8) Hulk
In an alternate timeline, the world is destroyed by a nuclear explosion that kills most of the world's heroes. The Hulk survives and using his Bruce Banner intellect and his every growing Hulk powers, takes control of the world and leads with an iron fist. He opted to go the the name Maestro and ruled over his kingdom called Dystopia.