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

![Shadows coming out of shadows cast by
rocks](https://i.stack.imgur.com/tFjYg.jpg)

![3 of the 4 shadows that came out](https://i.stack.imgur.com/mT7ID.jpg)

![one of them close up](https://i.stack.imgur.com/BSzUR.jpg)

![another one, deafen toy a Hollow because of the
hole](https://i.stack.imgur.com/dcMIP.jpg)

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.

