Who are the shadows that speak to Grand-Fisher? In the first season at episode 8, before Grand-Fisher leaves for the world of the living one of the rocks casts a large shadows before 4 other shadows shoot out and take form on rocks around Grand-Fisher, they apparently speak to him as he replies that he'll go and deal with Ichigo himself

I am wondering who these shadows are and if they are related to Aizen or are they a separate faction that don't support Aizen









EDIT: got some screenshots, there are 4 shadows but we only ever see 2 close up
It's never specified exactly who they are other than than the fact that they're hollows but based on the fact that they appeared to be more humanoid than most hollows it's safe to assume they were Vasto Lorde (strongest form of natural hollow). They also could be some of the Espada pre-arrancar since Harribel (#3) was revield to have been a Vasto Lorde it would make sense for other high level Espada to Vasto Lorde as well.