WMG / Garo The One Who Shines In The Darkness

Shin, the rocker from Episode 6, has been turned into a Madou Horror.
His song was heard in Episode 10 in a music player despite his previous reluctance (and inability to perform well without a Horror's scale) to record it so he might have been forced. That or he just gained enough willpower and improved.

Hakana, Ryuga's mom, is the daughter of Kouga and Kaoru.
  • Jossed. Both Kouga and Kaoru married and have son named Raiga, the protagonist of Makai no Hana.

Yami wo Terasu Mono will be the story of...
...Ryuga restoring the armor of Garo to its original state, just like how in The Final Odyssey, Tiga had to regain the form he had in his series by regaining his light.
  • Ryuga himself said that the armor of Garo had lost its original shine at the beginning of episode one, so this theory is a very real possibility.
    • As of episode 15, this one seems confirmed. Ryuga himself noted that while the gold wave that's created whenever he cuts down a Madou Horror causes him pain, his armor glows in response. Therefore, he's determined to cut down all the Madou Horrors in Volcity, both to protect the city and to restore Garo's original shine.
    • Confirmed!!!

Ryuga's mother was a Makai Priest
But Ryuga doesn't know that.
  • Jossed regarding the latter if the flashbacks are enough, not that it would matter since she wasn't actually dead.

Yami wo Terasu Mono is NOT a sequel, but a PREQUEL.
After Taiga's death, Kouga was too young to become Garo, but a replacement had to be found in the interim. Ryuga is chosen, using a Makai process that allows someone outside the bloodline to carry Garo, but not without some unfortunate side effects like losing the shine. It's up to Ryuga to fix that shenanigan by the time Kouga is ready.
  • But Episode 12 of the first season shown that Zaruba has always been with Kouga as a child after Taiga died and Garo's sword was stuck at someplace (Kouga went back to it every now and then) until he grew up and was able to pull it. The guess above would be conflicting with that.
  • Jossed, the cast and crew has already confirmed that this series is set in the future after the first two series during the pre screening of Soukoku no Maryu

Ryuga's absent father was a Makai Knight
But like with the WMG that his mother was a Priestess, he doesn't know this. His father was likely KIA either when Ryuga was young or before he was born by a Horror, possibly even one connected to Kaneshiro. It's even possible that his father was Kouga's actual successor as GARO given all we really know about Ryuga becoming GARO is he found the sword. If his father was GARO, then when he was killed the Kaneshiro's did something to drain Garo's shine to create Madou Horror.

Takeru will replace the right hand he lost with a hook.
He used to be a pirate after all.
  • Jossed. It was replaced with a Soul Metal fist.

Kaneshiro Tousei is a descendant of Rekka.
In Garo: Red Requiem, his actor played Rekka's dad, and [[spoiler: Tousei reveals that his mother came from a line of Makai Priests, and he found a whole bunch of Makai Priest gear in an attic box, and taught himself some basics. It could well be that he's descended from Rekka, whose line has since diminished, much in the same way the GARO armor is diminished.

The film with Ryuga will feature Rian as a lead
Agri and Takeru will only make minor appearances though

T Ousei had some kind of field in Vol City that supressed Inga Horrors powers
None of the Inga Horror seen in this season did more than open their mouth disturbingly. Tousei had some device limiting their powers so they'd be forced to obey him (the Makai Horrors being the ones who have to listen to him anyway)

Agri and Takeru will have guest appearances in Gold Storm Sho (the series)

Someday Ryuga will face the Horror that was involved in the event that cause the Garo armor to lose its shine.

The armor was blackened by Zaji as a way of humiliating the Garo lineage.