While Re'Gra and Re'Fua were attacking the two Balou Ras, Re'Rel looked at the figure of the Chimera Ras, watching it penetrate the Water Cage little by little as it entered inside. Even when Re'Kha tried to accumulate as much Water Qi at the place it was trying to enter, it still overpowered the defensive structure, rather easily at that.
The Water Cage was created using 10 units of Water Qi. And, at all times, 10 units of Water Qi continued to revolve in it. Moreover, its charging capacity was ten breaths. So, for every breath, it was able to replenish itself by one unit of Water Qi.
The only reason it managed to withstand until now was simply because of how Re'Kha manipulated it. Whenever anything attacked the Water Cage, she accumulated most of the Water Cage's Water Qi in the attacked area, thwarting off the attacks.