The design patent can defend the combined design patent, right?

That's right. In patent infringement litigation, the defendant can defend in many ways, one of which is to defend the invalidity of the patent. If the defendant considers the plaintiff's patent invalid, he may file a request for invalidation or defend the patent invalid in the lawsuit. In the case of patent for combination design, if the defendant thinks that the plaintiff's patent is not innovative or does not conform to other provisions of the patent law, he may request that the patent for combination design be declared invalid. The defendant can support the defense by comparing and analyzing patents and providing relevant evidence.