The Curse of Nimiel was absolutely fatal.
Any ill-fated person that contracts the curse would never be able to escape from it.
'That is the general idea,' thought Reve as he baited the curse into his body.
Beneath his mask, his lips curled to form a smile, '...but titans never adhere to the mundane concepts.'
After infiltrating his body, the two curses sought to absorb all his magi, but suddenly they lost all control of their ethereal form and were hammered into liquid by a mysterious force.
'I'm a Nexus Cat. Everything I absorb is processed into raw power. Even curses like the curse of Nimiel.'
Reve could feel the internal black liquid in his body. Ultimately, the curse was destroyed and the black liquid represented the essence of the curse.
If he were to truly absorb it, he would reap bountiful rewards, but Reve wasn't interested in it despite his fervent desire for strength.
He had his path set already.