I wanted to mention this, since I've read a lot of complaints about how difficult and hated this scenario is, especially for true solo. I tried playing this with the deck I had used in The Three Trials, and it was clear it wasn't going to cut it. But I got two wins out of five tries with this deck by Michael R from this thread:
https://boardgamegeek.com/thread/1266898/questing-through-nin-eilph
It's a Spirit/Lore deck. I've heard that dwarf decks can work well with this one too, but I haven't tried it. I don't find this scenario enjoyable enough to stick around and experiment with it further. It wouldn't be that bad at all if it weren't for the Time effects.
Henamarth Riversong and Wingfoot make an effective combo here.