Kakashi would be observant. He would study the Death Korps of Krieg's strategies and formations. He might also be interested in how their strict discipline compares to the ninja code in the Naruto world. He would likely be the one to try and establish some sort of communication and cooperation between the two groups if it was beneficial for the overall situation.
Sasuke would likely be initially suspicious of the Death Korps of Krieg. He's always been cautious around new and potentially powerful forces. However, he would also be intrigued by their military might and might seek to learn from them to further his own power.
Sakura would probably be a bit horrified at first by the Death Korps' rather grim and unyielding appearance and tactics. But as she got to know them, she would see their sense of duty and loyalty and come to respect them. She might even try to use her medical skills to help the injured among them if there were battles.
Chapter 545, "Kiss Me", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with Truth or dare, I still choose dare!" He just didn't believe it, Jiang... and closes on I was wondering why you were so sheepish around us, I thought you had....
Chapter 158, "It's Time to Recruit Someone Who Understands Mysticism to Work Here", is the clearest early answer because it turns Flash Change's situation into a concrete plot event.
Chapter 157, ""Forced onto Liangshan", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. It opens with It was already the last day of Flash Change in his dream. and closes on I'm laughing myself crazy, do actors all have such strong....
Chapter 120, "Jiang Li Can Actually Do Acupuncture?!", is the clearest early answer because it turns Director Sun's situation into a concrete plot event. The chapter turns that into something concrete by moving from Facing the sudden and somewhat strange request from Jiang Li,...
Chapter 106, "The Beginning of the Butterfly Effect", is the clearest early answer because it turns Butterfly Effect Thinking's situation into a concrete plot event. It opens with Thinking of this, He Yun nodded with a hint of anticipation.
Chapter 165, "Boom! Jiang Yan is actually Su Yinwan's fanboy?!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from How come everyone else got a solid six points, and he ended up with...
Chapter 201, "Passing the Door Three Times without Entering", is the clearest early answer because it pushes Sister Li into a new phase or setting.
Chapter 378, "What if I said I have a way to find your daughter?", is the clearest early answer because it turns Destiny's situation into a concrete plot event. Early on, He Kejun's disappearance was related to an apprentice she once....
Chapter 301, "Stealing Skills", is the clearest early answer because the violence around Jiang Li becomes final instead of hypothetical. A useful checkpoint is the way the scene starts with Old Sir Jiang was somewhat puzzled. and follows through with Now he finally found an opportunity to boast!.
Chapter 327, "Official Announcement Entering the Circle!", is the clearest early answer because it pushes Weibo into a new phase or setting. The chapter turns that into something concrete by moving from Three hours later, the shoot was over, and Shen Lan personally picked...