The it and the thing are locked in eternal power struggle due to their being the exact same person. Doom and Mr. Fantastic are locked in eternal power struggle due to the stupidity of both of their powers and their inability to harm each other using them. The invincible woman and invisible woman are locked in eternal power struggle due to ther powers being... their powers. The Inhuman torch and the human torch are locked in eternal power struggle due to their both being heat resistant and only having the abilitiy to project heat.