Both starts with disappearance of the character & both belongs to horror genre. In both case viewers are left with questions what happens with disappeared character. Both of them contains bullies.
-Both are BL's
-Both made by Be On Cloud
-Both have some of the same actors
-Both have action
-Both have violent scenes and concepts
-Both have suspense
-Mature themes
-Both from Thailand
Both stories evolve on a friend that they wronged in the past and now seeking for a revenge. Characters are investigating on how the past incidents will lead them in finding person who's trying to kill them.
Similar themes of what is the afterlife, spiritual awakening, and revenge from another level.
The only difference is ThirTEEN Terrors is an anthology, with 13 different stories.