The historical drama's first season concluded on May 22 on Showtime, while a second season is currently filming in Hungary.
Jordan told The Hollywood Reporter: "I saw this a four-year project really. In the first season, I felt like it was my job to very carefully plot out the historical context.
"Now, as I'm writing the second season, I can get much more down and dirty much more quickly. It becomes much more drenched in blood."
The Michael Collins director added that Cesare (Francois Arnaud) and Lucrezia (Holliday Grainger) will become more "evil" in the new season.
"They've only begun to learn evil," he said. "I really did want to present them as characters who have learned to become the monsters that we know."
Jordan also revealed that he was "glad" to have produced The Borgias for television, despite initial plans to make a film version starring Colin Farrell.
"Colin Farrell would have been a great Cesare, but he's a little too old," he said. "I had spent so long with the imaginary image of these characters, it wasn't that hard for me to write ten episodes [for television], which actually became nine because we ran out of money."
The Borgias will return to Showtime in early 2012. The drama's first season will premiere in the UK on Sky Atlantic on August 6.
> More US Television news
Watch a behind-the-scenes feature on The Borgias below: