Being mentally linked is really convenient for spell-casting coordination. More so when it's a two layered ritual with a total of sixteen casters.
With care and precision (and a bit of practice, by now) they sculpt vast magical energies into the summon.
There is a flash of white light.
The room's ceiling is very high, at least three stores tall, constructed from green-blue stone in intricate archways. Once the light fades, it's possible to see sixteen beings. Not all of them humanoid, and not even the humanoid ones look that human. There is a winged man with pointy ears right in front of him. He stands next to a four-armed human-looking person that's at least eleven feet tall.
The winged man speaks first before his own vision clears. "Don't be afraid. We are terribly sorry for this disruption. Do you have any immediate or pressing needs besides knowing what's going on? Something urgent happening where we took you from?"