Who would have thought!

Liam watched in awe as the life of the elf flashed past his eyes, some parts slow, some parts fast. 

He already knew that there was some sort of time dilation inside here. 

The soul-blood beasts mentioned to him that they were kicked out immediately after entering but at the same time their memory was also erased. 

From this he gathered that the elven elder probably showed them what he was showing right now and then erased everyone's mind before sending them out.

Or the other explanation was that he was somehow magically perceiving whatever the elder was showing in slow motion or at different speeds whatever pleased the elf.

Liam did not pay attention to these things. What he focused on was what the elf was showing. He was fully focussed on the man's forging journey that was not much different from his own.