​The tattoo is inked over the heart and symbolizes sacrifice and time in some form or another.

This tattoo can be activated using an Action during which you stab a dagger or similar sharp object through the center of the tattoo and through your heart. Make a charisma saving throw (DC 15), if you succeed you manage to follow through and you instantly drop to 0 HP and fall dead to the ground, automatically failing all DS. Time is reversed 10 minutes back. Everything is exactly as it was then, except the tattoo is gone and you, and only you, have a strong memory of what just transpired. Make a constitution saving throw; on a failed save you immediately drop to 0 HP and die. If the initial charisma saving throw fails, you cannot bring yourself to take your own life and nothing happens.

Alternatively, when you take piercing damage, you can activate the tattoo using your reaction. If you do so you need to succeed on a dexterity saving throw (DC 15) to position your body so that the damaging object goes through your tattoo and heart. If you succeed the same thing happens as if you had used your action to activate it, but consider the charisma save an automatic success.​

Note to DM: You are the arbitrator of what this do. The intent of this is to provide a "reset". Be flexible with the interpretation of "10 minutes" and "exactly as it was", choose a point in the past roughly that long back, where it is reasonably easy to estimate the state of the world in regard to peoples location and stats (HP etc). You don't need to keep a running, timestamped log of what transpire.

Notes: Tattoo, Consumable