Rod Reiss

Rod Reiss (ロッド・レイス) is a member of the true royal family within the Walls operating from the inner lands of Wall Sina. He is the father of Historia Reiss.

History
Rod Reiss conceived Historia with an attractive maid and his lover and daughter were exiled to a land that he leased to Historia's maternal grandparents.

On the day that Wall Maria fell to the Armored and Colossal Titans' attack, the entire Reiss family went to a chapel to pray in the underground secret area. However somehow Grisha Yeager appeared and engaged Frieda Reiss in combat. Though Frieda possessed the powers of the Titan she was eaten by Grisha through the neck, and Grisha then proceeded to kill the rest of the Reiss bloodline with only Rod escaping, blindly fleeing as his family was killed.

One day Rod came to get his daughter and inform her that she would be living with him from now on. Kenny Ackerman and the 1st Brigade of the Central Military Police intervened and swarmed around Historia and her mother. Kenny questioned if Rod was familiar with these two woman which he then denied. Rod watched as his lover's throat was slit while she denied being Historia's mother. When the former serial killer moved in to kill Historia, Rod suddenly proposed having her enroll into the Survey Corps and hopefully die in battle. Seeing this as a fitting alternative the Central Military Police agreed to his demand. This was revealed later to be just a charade invented by him, as up until that point the MP making demands of the King seemed somewhat peculiar, and later on Kenny acknowledges having played along with Rod's plan to get her into the Scouts. Presumably Rod left with the Military Police.

The Uprising arc
Rod is later seen siding with Kenny in a plan to kidnap Eren Yeager and Historia, eventually succeeding, keeping Eren chained in a dungeon of some sort. For an unrevealed reason he says he cannot become a Shifter, but whether this is true or not, if there is something to do with the bloodline or if it is just his personal choice is unclear. His relationship with his brother, the host of the Controller before Frieda who was apparently Kenny's benefactor, is unknown.

After failing to convince Historia to inject herself with the Titan fluid and eating Eren, he himself ingests the fluid as he watches Historia free Eren. After ingesting it, he turns into a gigantic Titan considered by Levi and Armin to be larger than the Colossal Titan itself.

Rod Reiss' Titan then proceeds to ignore the Survey Corps membes underneath the Reiss Chapel and begins crawling towards Olbd District of Wall Sina, hypothesized to be drawn by the larger number of humans in that area.

Relationships

 * Historia Reiss - Rod is Historia's father, though she is an illegitimate child who is not accepted as a suitable heir to the Reiss Family and thus Kenny Ackerman was charged with her death and the death of Historia's mother. Rod came to get her to live with him, but the Military Police interfered and rather than take back his daughter, Rod was forced to propose an alternative where his daughter's chances of survival would be extremely low rather than see his daughter's death before his eyes. It is thus implied that Rod Reiss may actually care for his daughter. When Eren and Historia are captured, Rod Reiss embraces Historia with tears in his eyes, saying that he is sorry for what is happening, surprising Eren and Historia. The reason for this, may well be his intentions for one day giving Historia the powers of her half-sister.