Pretty sure SM made a lyrics video intentionally.
For those who somehow didn’t understand the lyrics and thought they were nonsense,
Summary:
The lyrics tells a story about “Will o’ the wisp” baiting someone to get closer -out of curiosity- so when the person walks towards this light, they get separated from the people. After the light fools them by creating an illusion, it eats them when they’re off guard. The more people it lures and eats the more it grows.
Words referencing Will o’ the wisp in the song:
Fire, Light, personal pronouns (like Giselle in the first verse “stimulating curiosity”)
Lyrics:
an intro foreshadowing what happens
basically the person is walking closer and closer to the light and leaving the people behind. You= the person, Me= will o’ the wisp, Them= the people.
irrelevant but SM released this song in June where the moon start the waxing phase.
The lyrics are so obvious here but lore wise this new world might meant the other universe, not sure.
It used to be said that The will o’ the wisp lure people to fairylands. So the writer might have used that for the story.
This is also very obvious and it describes that it lures people by creating illusion then eats them. Also calling it fire which is one of its names but also because fire grows the more it eats too.
No explanation needed
Anyway the thing this pokemon throws is the same thing as the flame above so it’s obviously inspired 
