Kuroryu is a pet that is obtained by redeeming the chipped black stone crystal. The crystal can be obtained as a very rare drop from Seiryu the Azure Serpent. The odds of receiving the item are 1/300 with a threshold of 60 in solo, 1/1000 with a threshold of 200 in duo, or 1/1500 with a threshold of 300 in a trio. When calculating thresholds, the combined sum of solo and group kill counts is considered. After the item is used, Kuroryu can be summoned from the pets tab in the hero interface.
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On release, examining Kuroryu while it was following the owner did not show any killcount, but using it to override a familiar would. This was fixed on an update on 10 September2018.