Tasha’s Cauldron of Everything contains the wondrous item spellwrought tattoo, which allows you to cast a spell:
Once the tattoo is there, you can cast its spell, requiring no material components. The tattoo glows faintly while you cast the spell and for the spell’s duration. Once the spell ends, the tattoo vanishes from your skin.
An instantaneous spell like fireball would end immediately after dealing damage. A concentration spell would end as soon as you cast another concentration spell. What happens if you cast a non-concentration spell with a duration from the tattoo – blindness/deafness, for example? Can you then cast it again on the next turn (or on the same turn, with Action Surge), assuming that the first target hasn’t successfully saved to end the spell?