stark

Starrk tried to live with other Hollows, but simply being near his presence caused them to lose their souls and die. Because of this, he became jealous of how the weak are allowed to come together and so wanted to become weak. In an attempt to escape his loneliness, he had split his soul into two, himself and Lilynette. Starrk didn't remember which of them they had originally looked like before they split and suspected that their original appearance corresponded to neither of them. Even so, Starrk wanted to become weak so that he could be together with a group and if that were not possible, he wanted to find someone as strong as him.
When he split his soul, he asked the newly formed Lilynette if she had a name. She told him and asked if he had a name despite the fact that they were both the same person. He told her and then threw her a cloth to wrap herself up in. As she asked him on what would they do now, he answered that they could do anything. She then asked where would they go and he simply responds 'anywhere'. He then assures Lilynette that no matter what, they stick together forever.
Starrk and Lilynette were alone when he was first found by Aizen. The two are sitting in front of mountains of dead Hollow which impressed Aizen who asked him if they had killed all the Hollows in the area. Starrk told him no as they just died. This further impressed Aizen, who remarked to Starrk that he seemed strong. Aizen then pondered a thought and told the Arrancar that he is searching for allies. Starrk then replies on what a coincidence it is as they too are looking for allies and asks Aizen if his allies are strong. Aizen told him to come along and find out for himself. Starrk agreed to join him, noting that Aizen looked like he could stay with them without dying.