After finishing Zillia's clothing, Kyrie went to harvest the mortal remains of her previous body before any scavenger or natural decay robbed him of the materials left behind. Without a proper tool, it was an excruciating job.
Even if most of her body was devasted, it had too many resources by sheer size and mass. And no tool was able to cut through it effectively. Not only excruciating, it was boring. 'I hope she has no problems with me using her old fur to make clothes...'
Of course, he could always use the fiery sword, but it cost too much energy to use, making it ineffective and cumbersome for extended periods. It could be for the better that most of the material in her was already lost by the time he went back for round two.