Kylar is convicted (rightfully) of murdering the queen of Cenaria. The new king is Logan Gyre, who is Kylar's best friend. Kylar allows himself to be captured. Logan has a choice: he can execute the queen's assassin to uphold the law, or he can release his best friend. Logan decides to be Lawful and sentences Kylar to death on the Wheel.
Logan can't go through with it, so he hires a Wetboy to break Kylar out. Kylar refuses to leave.
On the way to his execution, Kylar is pummelled by rocks and bricks by the citizens of Cenaria. The method of execution itself is horiffic: the victim is strapped into a wheel lined with inward pointing spikes. The wheel rotates, and if the victim loses their grip on the wheel they are shallowly impaled.
Because Kylar heals from injuries so quickly, he is still alive the next day and appears to be barely injured. Logan had planned to meet with an ambassador in front of the wheel while Kylar's body was being removed, but instead ended up holding the meeting over a field desk, while his best friend dies slowly behind him.
Doubling as a Crowning Moment of Awesome, Logan begins to lecture the ambassador, and in doing so forces the ambassador to watch the execution. Partway through the meeting, Logan stands up, kicks over the desk, rips off one of the table legs, walks over to the wheel, breaks Kylars arms and legs, stands there for a minute until he's dead, and then walks back to the ambassador and delivers an ultamatum, while brandishing the bloodstained table leg. And that is how you write an emotional character death.
Jarl's death. He confesses his love for Vi- just as she shoots him dead with an arrow. Just to twist the knife, the bowstring slipped and she wasn't going to do it.
Everything to do with how the Black Ka'kari's immortality works. Everything.
After Logan learns Kylar plans to kill Queen Terah, Logan does everything he can to convince Kylar not to go through with it, convincing Count Drake to formally adopt Kylar and making him a noble truly. And when that doesn't work, he tries his hardest to get Kylar the quick death instead of an agonising one.