Age of Defiance (AoD) treats the Ronin Warriors Original Animated Series (OAS) and the Gaiden, Inferno, and Message OVA's as canonical and sequential. Aftermath picks up shortly after the ending of Message, and thus the guys are rocking their 2.0 duds. While AoD tries as much as possible to incorporate background lore and details from the original Yoroiden Samurai Troopers (YST) universe, some names, locations, and items are spelled differently mostly out of personal preference. Ronin Warriors probably has the most in-depth, complex world-building that just never made it outside of Japan, and that is simply a shame. The original YST series celebrated its 30th anniversary not long ago and kind of flew under the radar aside from a line of limited-edition figures and collectible statues, an extremely rare artbook, and a limited-time cameo event in a crappy gatcha mobile game...
The spiritual attributes from the original 1995-6 airings of the OAS are used, meaning Sage's attribute is still Wisdom, Rowen's is still Life, and Ryo's is still Virtue. Rowen is the oldest Ronin Warrior and Cye is the youngest. AoD uses the ages altered for the American OAS airing. Because of an episode in season 2 where Seiji(Sage) is seen driving at age 14, the American dub circumvented this by "aging the guys up". Thus in Aftermath the guys are in their late teens approaching their 20's. The ultimate attacks still use the OAS commands. Yes I get that they 'fixed' things for the OVA dubs, but I do not agree with that decision. I believe they should have kept it consistent and acknowledged Ronin Warriors and Yoroiden Samurai Troopers as similar but separate continuities much the same way as Beast King Golion/Voltron, Science Ninja Team Gatchaman/G-Force/Battle of the Planets, and Macross/Robotech are regarded.
Because this is a work of fiction, creative liberties are taken in regards to some Core Cast characters while attempting to incorporate as much canonical background lore as possible. For example in YST canon, Ryo is an only child and his mother died in childbirth while his father is still alive. In AoD his father was killed some time between Inferno and Message and his mother is still alive but in hiding with a kid sister he never got to know. He also has another sister who was presumed killed but makes her return in Chapter 2. AoD uses the "Rai-oh" pronunciation instead of the "corrected" one. Personally it just makes me envision fire (pyro) and that's simply the version I remember best from my youth, although some of the honorifics used by Allies use different pronunciations i.e. Raeo Flamerider (Ray-oh) and RyoTakin (Ree-oh). Also I'm Texan and Rio is a river that dances across the sand...
The Big New Yawkah is back. I don't get why they dropped the accent in the OVA dubs, maybe it was a creative decision or maybe Ward Perry didn't feel like doing it, but honestly it just suits Rowen. There is a bit of a running gag in AoD where new characters assume Rowen is from New York and he has to correct them that he's from Osaka. I've heard that it was common practice to give polite characters an English accent to emphasize their personality, but Cye's suits him as well, and there actually is a historical character named William Adams who was BFFs with Ieyasu Tokugawa back in the day, so even though Cye is of Japanese descent it's entirely possible for some English DNA to have noodled around his bloodline at some point. He does have a tendency to go "full British" when he's pissed off enough, though...
Age of Defiance is treated as a continuation of the Ronin Warriors OAS and written in the vein of old-school Saturday Morning animation, meaning there will be serious subjects touched upon alongside periods of levity. There will be crazy antics, tongue-in-cheek humor, gadgets, over-the-top villains, plucky side characters, and vehicles much like traditional 90's era fare. Age of Defiance and its seasons (Aftermath, Foes From Another World, Fight Alone, Cataclysm War, and Spacequake-ongoing) are intended for fans of the Ronin Warriors OAS, Shonen genre (boys), Sentai genre (Superpowered Team), and 90's animation in general. Songs used for background music belong to their respective owners and are part of my "AOD Soundtrack" personal playlist I use to help set the beat for scenes. Characters original to Ronin Warriors/Yoroiden Samurai Troopers belong to their respective owners (Sunrise, Bandai, and Hajime Yatate, which is apparently a brainstorming group and not a single person like I mistakenly believed...) Anyone interested in learning more about the OAS is welcome to check out the Samurai Heart wiki or Theria's YST Archive. Characters, locations, concepts, and items unique and specific to the Age of Defiance ficverse (Tanya, Danae, Raurgoth, Roxi, Shannon, Brianna, Black Hawk, Dygra etc.) are my creations.
It's fanfiction! Have fun!