Complex sentence: Sasha Fierce, it was reported that American R&B singer Ciara, who was working on her third studio album, "Fantasy Ride" (2009), had remixed "Diva", which was supposed to be included on her "Fantasy Ride Mixtape".
Split into simpler sentences: Sasha Fierce (2008), it was reported that American R&B singer Ciara, who was working on her third studio album, "Fantasy Ride", had remixed "Diva". The remix was supposed to be included on her "Fantasy Ride Mixtape".