No kisame samehada, but this worked for me at 172k with difficulty reduced 3 times

Thanks for the guide Oppai with *teration to suit my roster and a lot of luck I finally got it.

Essentially following your same game plan.

Second phase Round 1 (Note: this unsurprisingly took numerous attempts to get the luck not to have main controlled:)

Waited for tobi's interrupting chase to go

Main clear debuffs

madara standard started a chase

Waited for gaaras barrier to go up

Konan mystery

Gaara mystery

That just left midnight blade/orochimaru and hiruzen standing

Just about hanging in there myself though only gaara and madara left with about 16k health between them

Round 2

Madara on orochimaru, managed to finish him off

Madara standard took out midnight

Hiruzen finished my gaara

Rounds 3-5

Just madara and hiruzen left.

Nothing left to do but cross fingers at this point and hope madara and his ignition finish hiruzen before his mystery can take you down

Thank god for madara being immune to hiruzens standard is all I can say

^ that was how it went for me, eventually, in case its of any help to others