Ephemeral Rift has his own special breed of ASMR which of course is seen in a multitude of his videos and the characters he creates. If you don't follow science fiction very closely than you might be a bit confused as to what all of these things are. Things like Arkham, Deep Ones, and the sanitarium all might just seem like zany visions if you didn't know the name H.P. Lovecraft. Lovecraft was a Science Fiction writer who wrote weird stories generally set in New England with characters such as Deep Ones and Cthulhu.
How does this relate to ER? Well he obviously is very interested and invested in Lovecraft's stories and has made them into a series of ASMR videos. He has set many of his videos in the Arkham Sanitarium which is referenced in Lovecraft's stories. He has even gone so far as to create his own characters within the Lovecraftian universe.
ER's Lovecraft Characters (feel free to add any I've missed):
The Repairman (certain relations to Prof Clemmons, so i included him)
Arkham Hunter (Daniel Upton)