Hello,
first, many thanks for the saves set,
and found also save 6 A LOT easier than save 7 to get "Power of 100 "
Save 7, i go to kuchihagara, but the chain kill often ends at around 90-99, the last ones are too far away, even when you move your starting position.
Then where exactly, in save 6?
Load save 6, it's in hard mode, but fakeshadow gave us a great save set, you have to be dumb if you die with the special lifebar we have

Turn 180° after loading (you're facing the wrong way), and run, you're entering Amana castle.
Video (you can skip)
Following the flow you run now to the tiny bridge to your left, after that, you enter a really small area before going in a little garden (there's a tree), don't enter the garden, stay at the stairs or near the door, near the small area between the garden and the tiny bridge.
Wait for a soldier to attack you, parry (R1) and press X quickly, after entering the Hisatsu mode, wait near the door where are the stairs for an other soldier to come at you and gives you the possibility to enter the Rensatsu mode and you can here chain around 115 soldiers (that's my count with a failling start at 7, then i did 115)
I think it's a better place to get that annoying trophy than in save 7, you can fail a bit, there will be still more than 100 soldiers to kill, and it's small, but not too much, you can chain in the rensatsu mode easily and quickly (don't forget the start trick mentionned in other posts !)
I got it in my second try here, and failed my 11 tries with save7 (3 times at 98-99, and last ones too far :/ )
Hope someone understands the place i point
Never give up !
EDIT PS : I forgot to say, if you want to "run" when you're in fighting mode, press and hold R2 to run instead of stepping. (you won't need it, but just in case you want to do some replacing quickly)