https://www.pixiv.net/en/artworks/78472065

So, there seems to be an ongoing saga on this pixiv account of various Idolmaster characters getting killed, as the descriptions are full on stories. If not the entire series than at least the one I'm linking… There's a few english words and phrases and this one is the most foreboding:

>“Hazard On！——Are You Ready？Uncontrol Switch！Black Hazard！YABEEI！”

Because that kinda sounds like something you turn on to summon the tentacles you'd see later in the image set.