This one the hardest difficulty is actually fairly flexible, I think there might be a couple ways to do it but my sequence was:
Go south to the "bottomless pit" then go northeast to get your gag soaked by the stuff in the bottle. Then head through the waterway. Next go south to the other fairy. Go north to the rest area and then when the fairy points out one of the pink buttons, choose the other pink button. Now burn off the bindings in the lava area and go up the rope. Make your way back to the bottle and pick it up, and then this time take the right fork with the trees that grab the fairy. You can bottle the fairy. Finally, go to the left fork instead of back to the fairy route.
For hopeless you have to go right slowly instead of down at the start. After that just follow his guide and you will get revived by the fairy due to it feeling remorseful.
There are two issues with this as a solution for the hopeless difficulty.
1.On the hopeless difficulty, you can't survive the open-sesame location when you have the fairy bottled. You'll punch the door, get a spray and even if you're at 0 enchanted, you'll go up to 100 from one go.
2. On the hopeless difficulty, you can't get past the area before the 3 buttons a second time. Because in anything up to merciless you can go through the room with holes in the ground. But on hopeless, there's a permanent wall, so you can only pass it once by going into the room with a carpet on the floor where you get undressed.
--
I've only gotten the ending where the fairy will let you go for being masochistic if you reach the end with legs bound. However, with bound legs, you have to go through the room with holes in the ground, for which the end part is closed on hopeless difficulty.
I've tried maxing fairy excitement (9 or 10?), I've tried minimizing it (3), I've tried walking through the end part with bindings and without, with enchantment and without. With having saved the fairy, and with not having saved the fairy from the tree. I've tried it with the waterway (of course by soaking gag in liquid). In each of these cases the Nikky will not let her go.