The Eternal Sanguine Reverter (used as a catalyst/secondary input in the Alchemical Reaction Chamber or ARC from Blood Magic) does not function correctly. The base item has a durability of 32, and only one durability is used each time an input is processed. The Eternal version is consumed upon using it once. It doesn't stay, as you might expect an eternal item to. A GIF/video displaying this bug in real-time can be found here:

(btw the reason the progress bar skips is just because I used a 2x buff on the ARC from bottle of time so it would fit in my 7-second gif recording limit - I assure you this still occurs without the time buff)

I first discovered the bug in 0.4.28, then changed to 0.4.29 and checked - the bug persisted.

I am considering posting this on the Blood Magic issue tracker, but it's really an interaction with Forbidden and Arcanus, so I felt the pack would be the first and foremost place to include this in case it is something that can be addressed on the pack side.

The easy solution from a pack perspective, is to just add that to the blacklist of things that are not allowed to be made eternal, i'll look into it

Fixed in 0.4.30 by disabling Eternal for that item.