What people didn't realize is that he was referring to me. I'm a genii, freed by a group of Nazi mystics working with magi from the defunct Ottoman Empire. I proved unctontrollable. In 1939 an ultra-top secret group, involving personnel from the USA, the British Empire, Nazi Germany, and the Japanese Empire, managed to freeze me in liquid nitrogen. During the past 70 years, my powers weakened. Arachnos has freed me. While restoring my full self, I am willing to work with his forces.
I was lucky to get the name Fear Itself. I'm sure over the years, other folks on Infinity tried and failed to get it. Several folks told me that I should not use "genii" in the description, but jinn (or djinn) instead. Checking now, they were right. Oh well; I think it's a good description anyway.
For his look, I went as monstrous and evil as I could. I'm sure there are those who could have done better, but I know I don't want to open my bedroom closet and see that.
He didn't start out as much of a soloist, but teamed, he was a significant asset. Late in his career he started slotting purple invention sets. Those, and his other sets and high-end powers allowed him to solo very well. Even then, he'd normally be teamed. (Why play a multiplayer game and then solo?)