Lindyrm is an Abyssal+lord mentioned in The Deva Spark.
The author of The Deva Spark, Bill Slavicek, said this on ENWorld:
"As far as I can tell, Lindrym was created just as a backstory
antagonist for Deva Spark. I can't recall if I made up the name or if
that was one of the things we salvaged from the original designer's
manuscript. Either way, it was just used as flavor and as an impetus
for the motivations of the characters in the adventure. No additional
material was ever created. Though we might resurrect the name in some
future product!"
- 585 reads