It was through Swimming Dragon's words that Lu Yuan suddenly realized.
It seemed that the three Sure-kills of the Crane Sect—namely, "Crane Shadow Floating in the Air," "Mistakenly Picked Immortal Orchid," and "Penglai Vastness"—were all offensive moves. None of them were defensive.
This was indeed unusual. A martial arts tradition, after hundreds of years of inheritance, perfection, and improvement by countless disciples, should be relatively mature, even if not perfect. It should entail both offense and defense—that's the basic principle.
At least in Swimming Dragon's Dragon Sect, there was "Dragon Hide Body" that could be used for evasion and defense. But the Crane Sect had none. It wasn't that they were missing; they simply didn't exist within its tradition. Such techniques were likely part of the Snake Sect's heritage.