Now that I'm at E-7 I can relate to this. Given how good this is going on Easy so far I think I can complete it in 24 hours... 48 at worst. I only need a bit of luck.
I tried to clear E-7 Hard mode using Surface Task Force.
DID
NOT
WORK
OUT
Just went with Carrier Task Force (2 BB 1 CA 1 CV 2 CVL + 2 CA 1 FBB 2 DD 1 CL) and defeated it
Summer '15 Event E-7 Lower Route
Spring '14 Event MembersNode Ⓑ
Submarine So-Class
First Appearance
Spring '14 E-4 BossNode Ⓧ
Seaport Hime
First Appearance
Spring '14 E-3 BossNode Ⓨ
Isolated Island Oni
First Appearance
Spring '14 E-5 LAST BOSSNode Ⓛ
Battleship Hime
Spring '14 Event E-5
True Last Boss?