Possible Clues:

• If mine is a split personality, that'll be the ruination of me
• Damage this writer's popularity, primarily with publicity
• Reduce brat with a look
• For there to be two Crosaires would rather spoil it
• It will spoil me to be a split personality
• There's two of me, enough to spoil me
• It would spoil me to come at the double like this
• Perhaps having a mischievous appearance is enough to spoil me
• Being a brace does me no good at all
• Injure, damage