Normally I am not a fan of slang like "Lit" in translations, unless it is the japanese equivalent. (God saying that makes me feel old) That said, Cid is one of the characters that it just works for. He strikes me as the type who would throw in the "Cool Kid" slang every chance he gets for shits and giggles.
Also I can see him rewarding Rose by clearing her name or by letting her join Shadow Garden properly as thanks for providing him the perfect end to the tournament. Gets to not only disrupt it with a cool brawl, but gets to shine light on the shadows playing behind the scenes. I don't think he could have came up with a better ending if he gave it his all. I could also see him thinking that this ending is so perfect that she is obviously working with Alpha and the gang to set up a perfect play for him. Thanks to that I could see him then whisking her away and leaving her with Alpha, thanking them both for their work, which then leads to Alpha mistaking it as a recruitment test for Rose leading to her joining Shadow Garden that way.
Gods this manga is just so damned good. I can come up with so many bullshit ways the story will go and this masterpiece of edge will cut them all to pieces and somehow do something even stupider. The day this finally finishes up or gets axed will be a sad day indeed.