The Mark removal overwrite-failure is fixed now.
The 1 hour removal time is from my proofreaders; they had an issue with 1 day removal times, so I dropped it down from 1 day to 1 hour. Because of how quickly an Inugami can layer Marks onto a target (assuming Barghest entry they can manage 4 per round by trading all Natural attacks in a Full Attack for Marking attempts, then Mark one target as a swift action) I don't have an issue with Marks falling off quickly and, besides all that, it keeps the time increase a bit more consistent (1 hour->24 hours is a massive jump that makes 10 minutes->60 minutes seem much more reasonable.) If I ever get around to playtesting this I'll see if Mark removal needs a #/day limitation, but for now it should work pretty well.
The "d20 and Damage" version limits things like 'Barghest Feeding causing soul destruction', which was something I definitely wanted to include. On the other hand after chewing on the wording for a bit I can see how this could be problematic with things like Prismatic Spray or Enervation, should the Inugami acquire spellcasting. I put in a temporary fix, but if you have any suggestions for wording it more elegantly I would be glad to hear them.