Gerulf had not changed. If Jake were to describe his transformation... He would simply say that Gerulf was even more like Gerulf than before. His face with its intimidating, bestial features was unchanged, but his lower canines had grown, as had his claws.
He also wore heavy hoplite armor with a gladius at his belt, and held a rectangular shield and spear that made him look anachronistic among the crowd.
His musculature and growth spurt, on the other hand, had exceeded the bounds of reasonableness. In the past, the giant towered over him by two heads, and it was still the case today.
To his dismay, he still had to lift his head to look him in the eye, but it made him smile instead. Time flew, the world changed perpetually, but there were also things that remained the same. Strangely, this brought him some solace he didn't even know he was craving.
Why Lucia has aged more than him, the logic behind it has already been explained relatively clearly in past chapters but I'll come back to it.
Why she is so moved when finally she and Jake didn't know each other that well, it's complicated to answer, but she owes him what she is today. Without Jake, she would have remained a fearful, downcast princess, meekly controlled by others. When it all falls apart, it's no wonder she clings to a promise. In the long run, it becomes an obsession and the feelings grow.