Isabel did mention something along the lines of "the sins of the father", which may imply that she has a personal vendetta against the Queen family. When news first broke of Summer being casted as Isabel, I recall that there was some stuff of her backstory in the comics that have been posted on this site. One of the bits in her backstory stated that she had some sort of personal relationship with Robert Queen, Oliver's father. I think that it would be interesting if the writers delved into that a bit more and reveal how Robert hurt Isabel, leading her to hold a grudge against his entire family.
In the DC comics, Isabel Rochev is a villain described as follow:
Isabel Rochev is from a small village in Siberia, where she lived a life of servitude ,working in a diamond mine. When the head of Queen Industries, Robert Queen, came to her village, she was inspired by the man, who she saw as a symbol of ones inner power. She fell in love with him and whilst he may or may not have loved her, she found him a great source of inspiration and vowed to make something of herself and rise from her humble status as a slave girl.
She achieved this goal when, many years later, as well as after the death of Robert Queen, she became the new CEO of Queen Industries, having brought large numbers of shares in the company, though many smaller organizations that she owned. Her goal was, and still is to make the name of Queen Industries great again, after the company had continuously lost profit and support for many years. She would soon begin to provide her own personal private security forces to Star City, as the corrupt bureaucrats of the city, who were desperate to try to keep control of the population, after hundreds were left homeless in the wake of the events of Cry For Justice. With much of Star City destroyed, Isabel soon began to increase her influence over the city and become closer to power.
Isabel is a somewhat eccentric individual and often wears a mask to hide her face. She also believes herself to be the true heir to Queen Industries and the true love of Robert Queen's life. This gives her her single minded nature and she is also know to wear the jewelry of Robert Queens wife, specifically her wedding ring. Now "The Queen" of Queen Industries, she desires nothing more than to make the company's name great again and see the disgraced son, Oliver Queen killed, by whatever means necessary.
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