As the crystal prison formed around him, Shin extended every wire outwards and increased the density and durability to the absolute maximum that he could. Given the incredibly short time frame, of course. It gave him an incredibly small amount of room to move around, but it was something. For anyone else, this would spell out an absolute death sentence. Sealed within a crystal of unknown density with no real means of escape, and an incoming attack that would have completely bisected him. If only she had crushed him completely, rather than trapped him. Maybe if she had disarmed him before, she might have had a better chance. See, the way to escape any barrier is to increase pressure inside of it, and while he wasn't totally capable of filling the room he was able to emulate it.
By leaving even the smallest hole in his cage, she'd given him an escape route. Shin shuffled his body to the side and tilted the base of his spear, planting it against the base of the container and the roof at the same time. This created a solid wedge between the top and the bottom, and leverage is king in a world of hard cages. No matter how hard something is, if it's inflexible it isn't going to survive being pushed against in both directions.
His right hand was still firmly planted against the spear as the blade came rushing through the gap. If he hadn't shuffled himself off to the side it would have taken much more than it did, it would have diagonally sliced him from the shoulder down to his hip. On his right side it wouldn't have been immediately fatal, but it would have inevitably killed him. However, he had moved slightly. Putting only one part of himself in the direct line of fire, his right hand. It absolutely dissolved the flesh, like a hot knife through butter. His hand slapped down to the ground with a wet plop and Shin's face turned from placid and wicked to outraged in zero seconds flat. It struck against the base of his staff and broke apart, but most of the water had passed through perfectly smooth.
Once the water blade had passed, Shin sharply kicked against the staff. Nudging it forward and alligning the flat of the blade at the top with where the blade of water had come from. Like a can opener, he raised his foot upwards sharply into the bottom of his staff. It tilted his staff up and forward into the small groove, wedging it further in the cage. As he stood there, kicking his staff upwards his blood pooled at his feet inside of the container. The wires around his body had begun to dissolve, the part of the body that had connected them to the staff was severed. It gave him even more room inside of the cage, to which he responded by raising his left hand upwards in preparation for a shell cracking strike.
As he had his hand overhead he paused, realizing a second wave might come through. If he used his hand too soon he might lose his left hand as well, Shin would wait and prepare to strike again once a second had followed up or enough time had passed.