E-5 Stage Boss of the Operation AL/MI Summer 2014 event.
Basically Aircraft Carrier Oni with torn clothes and glowing red veins all over the monster-ship bits. It's easy to confuse the two.
As she sinks, she begins to talk normally instead of the usual reverberated voice of the abyssal bosses, a voice that is sometimes identified as Akagi, given how the event is essentially a re-enactment of the Battle of Midway where she was critically damaged and scuttled. Both even share the same seiyuu: Fujita Saki.