Though they did non-40K stuff as well about half a year ago they've been a very prolific 40K only channel these past few months.
Some really nice lore topics spiced up with great 40K artwork or fitting artwork from other sources when it fits the subject. Really liking it!
Edit: Forgot the link:
https://www.youtube.com/channel/UC0Tb8KvaNNhuErQjhVMfGfw