The Premature... Burial?

  You find a casket right outside the building. It's locked up tight, with at least five locks on the sides. There are keys on the side of the casket for each. You open it up, and what do you know, it's Cerulean! If you look on the inside of the casket, you can see scratch marks and lots of blood.. That's probably why his fingertips are barely there now! Of course, the casket wasn't underground.. Why was Cerulean dead if he had air to breathe? Why, that's a good question. You guys figure that out yourselves. Cerulean also holds a note. It reads, "Tʜᴇʀᴇ ᴀʀᴇ ᴄᴇʀᴛᴀɪɴ ᴛʜᴇᴍᴇs ᴏғ ᴡʜɪᴄʜ ᴛʜᴇ ɪɴᴛᴇʀᴇsᴛ ɪs ᴀʟʟ﹣ᴀʙsᴏʀʙɪɴɢ﹐ ʙᴜᴛ ᴡʜɪᴄʜ ᴀʀᴇ ᴛᴏᴏ ᴇɴᴛɪʀᴇʟʏ ʜᴏʀʀɪʙʟᴇ ғᴏʀ ᴛʜᴇ ᴘᴜʀᴘᴏsᴇs ᴏғ ʟᴇɢɪᴛɪᴍᴀᴛᴇ ғɪᴄᴛɪᴏɴ."