This is not my idea, but someone else(asked me to post for him, but edits are sure to come)
Rpable form of sst/sste
===SST===
Its raw form was the star meteor which they'd train with to gain exceptional skills and obtain a purple chakra that was stronger than anything they knew. Constant use would ware down the body(wiki)
The shinobi had traveled to Hoshigakure and upon getting the permission and help from the Hoshikage as a reward for defeating the rogue star warrior a large mass of star chakra was taken from the meteor and sealed in to a special tattoo on the shinobi's body. Due to it's regenerative abilities it won't die out of a few uses. Those bearing the tattoo are more resistent to poisonous chakra but even they are affcted by it reducing their life span to half.