Hi! My DM gave me a sentient ring that has the benefits of the ring of protection and the ring of spell turning, as well as a few spells that can be cast. I have to ask more about their limitations to finish inputting it. On the negative side it takes from my hit points once a year while wearing it (He was kind) I have to confirm by how much, but is there a way to add the negative hit point curse to the item? I have figured out how to do the rest, but taking away from the hit point max little by little at a specific interval is something I am still not sure how I would do it. There aren't good example items I can pull from on how others added it in. 

or 

would I just be better off just putting that in the description and manually changing it once the time comes since it is so infrequent? If so, is there a way to manually change it so it stays that way since from a lot of the older posts, it seems like there was not.

Thank you!

You would be better off putting it in the description and doing it manually, incremental things like that aren’t supported because the system has no idea how much time passes in game compared to in reality.