The whole thing isn’t just about Kael. Hestia had once admired all three of them so it must have felt like a huge betrayal when she saw how selfish Diana and Helios was and how it affected Kael. In her mind she must have felt how undeserving they were of all the blessings and happiness they were receiving. So the revenge was also for her who blindly supported them while not knowing what Kael was going through, until she fell into the novel’s world and saw it first hand. She also needed a reason to be there because it was too abrupt and confusing for her on why she was there in the first place. The revenge was a good distraction to her situation and it gave her a chance to fix a wrong that she felt needed a fixing.
The whole thing isn’t just about Kael. Hestia had once admired all three of them so it must have felt like a huge betrayal when she saw how selfish Diana and Helios was and how it affected Kael. In her mind she must have felt how undeserving they were of all the blessings and happiness they were receiving. So the revenge was also for her who blindly supported them while not knowing what Kael was going through, until she fell into the novel’s world and saw it first hand. She also needed a reason to be there because it was too abrupt and confusing for her on why she was there in the first place. The revenge was a good distraction to her situation and it gave her a chance to fix a wrong that she felt needed a fixing.