I also prefer the more eerie music of the original scene over the bombastic march.
I think some of Gordy Haab’s music could also be used for rescoring this series. He did the music for Battlefront and Jedi: Fallen Order, and I think he really nails the feel of Williams’ style without just repeating the same music.
For example, the theme for the Second Sister from Fallen Order could potentially be used as an Inquisitor motif that makes their appearances more menacing.
Also, maybe some stuff from the Shadows of the Empire soundtrack could also be used. I feel like that is another score that nails the Williams vibe pretty well.
I second that. Literally my thoughts as well.
Although the piano theme does have a nice ring, i think the horror is missing with it. But ultimately it´s your edit.
Anakins dark deeds could work, though.