Item: Exalted Servant Band

"Hey man, can I change my character? And I'd like to have a cursed item which eats my health." Sure thing!

One of my players wanted to switch out his character (apparently unsatisfied that his halfling had survived the session) and wrote up a nice back story - I'll paraphrase:

Mysterious organization kidnaps orphans to a woodland refuge during the Last War. Experiments on them with weird elixers and hurtful magic items. At the end of the war, a circle of nearby Druids break up the nefarious scheme. Any surviving orphans get a potion recipe to help fight off lingering effects from the research.

The character now wears a non-removable metal band with 3 dragonshard crystals around his bicep. Every long rest, roll 1d6:

1d6	Level 1-3	Level 4-6	Level 7+
1	One level of exhaustion	One level of exhaustion	2d3 hit dice spent
2	1 hit die spent	One level of exhaustion	2d3 hit dice spent
3	1 hit die spent	2 hit dice spent	2x level damage
4	1x level damage	2 hit dice spent	2x level damage
5	1x level damage	1x level damage	1 year of your life
6	2x level damage	2x level damage	1d3 years of your life