I think what really got me excited was Murdy talking about all the scarecrows having glowing red eyes.
I know it sounds like something really small but thinking about it... We don't generally see costume that have special effects very often.
Sure we've seen the statues in La Llorona, Devil Demon from TITE, and some of the Purge masks but looks like it is starting to become more commonplace.
A bit off subject but I think Mummy was also using some LED effects timed with the audio. I think as the technology develops we're going to begin to start seeing some crazier costumes.