My analysis of Kao Cen Darach will reference multiple academic sources, such as The Jedi Path, the Journal Of Gnost-Dural, and The Old Republic Encyclopedia, but it is primarily extrapolated from his lone media appearance, the Return Cinematic Trailer. As should be obvious, my analysis of Asajj Ventress will be based purely upon classic Legends material, most notably the Clone Wars microseries and the Dark Horse comics, excluding her appearances in The Clone Wars animated series and all of its tie-ins, particularly the New Canon novel, Dark Disciple.
To summarize, Ventress in "Legends" was effectively Dooku's pet serial killer, a deeply disturbed individual who would've been a natural fit for NBC's Hannibal. By contrast, Ventress in "Canon" was a weak pantomime villain jumping from one parental substitute to the next, spending most of her run as a disposable lackey to whichever master she happened to be serving, and when she finally did step up and start calling her own shots, she got herself horrifically murdered. In essense, the writers of TCW got Ventress' character ass-backwards, stripped her of her iconic weapons, stripped her of her iconic appearance, then killed her off in a crappy harlequin romance novel.
To hell with that, Legends all the way.
And with that bloody noise out of the way, let us proceed with Kao Cen Darach Vs. Asajj Ventress.
[06:55] - The Old Republic Encyclopedia, Pg 258, Sentient Species - Zabrak
[07:14] - The Jedi Path, Pg 114, Jedi Guardian
[10:13] - The Old Republic Encyclopedia, Pg 261, Sentient Species - Rattataki
[10:32], [35:03], [36:51] - Yoda: Dark Rendezvous, Chapter 1
[11:18] - The Cestus Deception, Chapter 51
[14:29] - The Jedi Path, Pg 118, Jedi Guardian - Lightsaber Instructors
[16:17] - The Old Republic Encyclopedia, Pg 85, Leaders of the Jedi Order - Grand Master Satele Shan
[16:35] - The Jedi Path, Pg 138, Additional Lightsaber Techniques - Trakata
[18:07] - The Old Republic Encyclopedia, Pg 168, The Sith - Darth Malgus
[20:04] - Jedi Vs. Sith: The Essential Guide to the Force, Pg 139, The Dark Side - Dark Side Disciples
[22:11] - Clone Wars microseries (2002-05), Chapter 22, Audio Sample
[24:17] - The Cestus Deception, Chapter 77
[24:20], [37:01] - Yoda: Dark Rendezvous, Chapter 8
[27:20], [28:32], [28:57] - The Journal of Gnost-Dural, Pg 21, Chapter Two: The Return of the Sith Empire
[29:12] - The Jedi Path, Pg 69, Lightsaber Forms - Form III Lightsaber Combat: Soresu
[33:22] - The Cestus Deception, Chapter 25
[33:32] - The Cestus Deception, Chapter 29
[34:50] - Tales of the Jedi: Dark Lords of the Sith - Issue 3, Descent to the Dark Side