D&D 5E Need help creating a cursed item for my campaign

[guachi]

In addition to all the truly creepy things listed above (it's like a thread of budding Stephen Kings) if you give the thumb gradually more power or just useful powers to begin with the players will easily corrupt themselves. In my current campaign the party of six 5th-6th level PCs had one of them get magic jarred by a crazy and evil 11th level wizard. Sure, they knew something was up but, hey, 4th, 5th, and 6th level spells! She could solo tough creatures! They'd deal with it later, right?

 

[PSusac]

These are great! Thanks!