The Shadow Thief hasn't been completed. No Reef characters ever says anything about it, and the HoW Quest doesn't include it. We also don't know who hired Taniks, so he could have easily been hired by the Wolves following Orbiks Prime during TTK instead of Skolas during HoW. Not that I really can see a reason for this, but the fact that Ghost mentions that the Fallen broke into the Hellmouth during Lost ot Light is something worth thinking about.