BTS at 2018 MAMA in Hong Kong: Airplane pt. 2, O!RUL8,2? (LY Remix), and IDOL

I am shook with the performance of "O!RUL8,2?" LY Remix. There was confirmation that RM was going to be performing one of his solo songs and there was a lot of speculation as to which one it would be, but I did not expect it to be "O!RUL8,2?" 'cause damn, that's a throwback for real. It was the first time I have ever seen it performed live and it was fucking bad ass. However, there were rumours flying around that Jimin was going to have a solo stage at MAMA because of recent fancam pics of him having the same "NEVERMIND" tattoo on his rib cage as he had for the MAMA stage in 2015 . People speculated that it was a temporary tattoo, maybe henna, for one of the year-end award show performances. But now that MAMA is over and Jimin stayed fully clothed (probably to everyone's disappointment), my question now is... is the tattoo real, is it for a different performance, or does it have something to do with Jimin hinting at the release of his own song at the end of this year?