Some TMNT stuff really isn't for little kids.
Aka is a the eldest child of the Dragon, a member of the Pantheon, and sister to Manmoth, Gothano, Chi-You, the Rat King, Toad Baron, Jagwar and Kitsune. Unlike most of her siblings, Aka is fond of humans and mutants, considering mutants to be the Pantheon's true children. Aka is friend to the human April O'Neil.
Aka expresses herself as a kind old woman. As the eldest surviving member of the Patreon, she takes her position seriously and loves all her siblings as family.
But unlike most of the Pantheon, Aka also loves and respects humans, considering them to be the Pantheon's true children, and wants to give humanity a fair chance of succeeding on its own merits. To this end, Aka has befriended and supernaturally aided April O'Neil, a human woman. However, Aka is clear that this fairness she seeks for humanity is not a guarantee of their success but merely honoring their right to pursue their own destiny without unfair sabotage, accepting that humanity may still yet die out as a result of their own failures.
Because of Aka's decision to intervene in human affairs, her relationship with her youngest sibling Kitsune has been damaged. Aka and Kitsune ideologically differ on the fate of humans, with Kitsune eager to see humanity annihilated.
In the Teenage Mutant Ninja Turtles: Casey & April miniseries, April O'Neil meets Aka while she and Casey Jones are traveling in the southwestern United States. Aka explains to April some of the history and nature of the Pantheon, including the ancient struggle between its members and Kitsune's membership of the group. At the time, Aka is amicably neutral in human affairs.
In issue #60, when Kitsune has begun her rampage through Foot Headquarters in an attempt to depose Splinter as jōnin of the Foot Clan and seize Oroku Saki's remains, Aka appears to have a change of heart, giving April access to a supernatural artifact and incantation to temporarily suppress Kitsune's mind control powers. This turns the tide of the battle, forcing Kitsune to flee Foot Headquarters. The Rat King is surprised at his sister's decision to start taking sides.
Aka's decision was the cause of friction between the sisters in the Pantheon Family Reunion arc. Kitsune felt betrayed by her sister siding against her, though Aka made it clear that it was nothing personal against her youngest sister. When the Turtles were found to have infiltrated the Den of Delights, Aka pleaded with her siblings to show mercy to them, but was ignored.
- Aka shares similarities with Onida, a supernatural character encountered by April O'Neil in the Mirage TMNT story White Horses. In that story, April takes a solo road trip to a remote island in the Pacific Northwest to contemplate what she believes is her imminent death. She meets and befriends Onida, a kind elderly Tlingit woman. Onida helps April deal with her existential crisis at having recently discovered she was not born human, but drawn to life by her father using a pen and a warp stone. At the end of the story, after parting ways with April, Onida turns out not to be human either, but the spirit of a deceased white horse who had assumed human form to encounter April.
- Aka is called "Red" as a nickname by her brother the Rat King. The word "aka" is Japanese for "red."