Gandalf flew to the top of a mountain and tried to calm himself down from the uneventful experience he just experienced.
Ordinarily, this was supposed to last for a few minutes but it didn't stop even after hours of trying to calm himself down.
An Achlys. Usually, when someone encounters them, they don't tend to have this much effect but Gandalf could not understand why Titan had that much darkness in her. It seems she is even darker than he thought considering the fact that he was still in his dark phase till now.
An Achlys is a very dark creature that brings out the darkness in other creatures by any form of body contact. They were extinct for more than three centuries but now, he encountered one when he least expected.
And not just any random Achlys, this was a very powerful one unlike he had ever seen in his entire life.