In episode 24 of Durarara!! ×2 (the last episode of Ten), Izaya identifies himself to Vorona as one of her previous clients.
What did Izaya actually hire Vorona to do?
It was Yodogiri who hired her and Slon to abduct Awakusu Akane, and I don't seem to recall having been told who hired them to attack Anri (and in any case, I don't see what Izaya's motive for having Anri killed would be, though his motives are admittedly a little bit opaque at times). Am I forgetting something?