He took you by force to the Phantom Troupe hideout to replace Uvogin. They didn't know your abilities yet but wanted to see them so that you could be the replacement.

Shalnark had you tied up in front of everyone

As you can see, I brought you here by force to see if your skills are useful to us

Chrollo was looking at you, Machi, Shizuku and Feitan were looking at you with distrust