The Borgias/WMG

Assassin's Creed Brotherhood Crossover WMG

 * In the finale, the entire cast will be killed off in an arrow storm.
 * In the series finale, Ezio Auditore will make a cameo appearance as the one who kills Cesare.
 * Given Ezio's line to Cesare before killing him (translated) "May no one remember your name" Showtime is either run by the Templars or the Assassins realising that the Borgias are remembered are using the series as one big Take That.
 * It turns out that Ezio..is Micheletto.

Juan will not be killed by Cesare, but by Gioffre
Yes, this sounds very far out, but when the historical Juan was murdered in 1497, suspicion was not only cast on Cesare, but also on his youngest brother, allegedly because of the affair between Juan and his sister-in-law Sancia of Aragon. As of now, we know that this affair did happen in the series. Wouldn't it be fitting if Gioffre (who would be 16 years old by then, if the series follows the historical dates), the Oblivious Younger Sibling, turns out to be the one who actually goes through with killing Juan (Lucrezia already tried, and Cesare was close to trying). It would be a nice twist, since apparently everyone in the audience thinks it's a Foregone Conclusion that Cesare will off his brother (including on this wiki). It would also put a much greater strain on the relationship between Rodrigo and Cesare, since Cesare would naturally be the prime suspect, but may be completely innocent.