Well, s**t. Episode 9 - the penultimate episode, and boy was it insane. I'll start of by saying that I am honestly not surprised by the revelation. While discussing the season with my mother, I did speculate on the High Priestess somehow acquiring Aku's essence to bear children. And.....yeah, that's almost how it plays out. In the episode, Jack and Ashi set out to slay Aku, but Jack initially leaves her behind, because he had lost everything that he had loved at that point....he didn't want her to be just a memory as well. And then, it gets worse. Scaramouche and Aku arrive, which causes Aku to realize that Jack still had his sword, ergo obliterating Scaramouche. As he was about to leave, Aku notices his essence from within Ashi. It turns out that "Daughter of Aku" was as literal as one could get. In the past, Aku paid a visit to the cult, and pleased by their worship, humors them by giving them some of his essence. Which he didn't expect the High Priestess to drink it. So, for all intents and purposes, Ashi really is his daughter. Of course, Aku then uses that to his advantage in which he forces her to fight Jack. Jack couldn't bring himself to kill Ashi, Aku stands victorious, the sword gets taken from Jack again....the end.
Now I did like this episode, but I felt undermined. I knew that Aku could potentially be Ashi's father as she is able to do things that go beyond her training, such as when she completely obliterates the Orc army without breaking sweat. To me, the twist that Ashi was his daughter was kind of predictable. Having the bad guy be the hero's father or whatever is pretty cliched at this point. It's just not surprising to me anymore. Of course you have to feel especially bad for Ashi; she is fully conscious as she's battling with Jack, and doesn't want to hurt him, but her father is in full control of her body. Wow, guys...you make Jashi canon only to then tear it to pieces as it suggests that Jack has to kill someone he came to genuinely loved in order to be forever rid of Aku.
As for the Guardian. Even though Jack and Aku had both said that the time portals had been destroyed, many speculated that the Guardian's portal must've been hidden away. Of course, when season 5 was announced, many asked if the Guardian will be returning. I mean, it seemed as though they had forgotten him. Of course the directors didn't forget this important aspect - as with the prophecy - so in order to work around this plot point, it is shown that Aku had destroyed this portal as well, and also killed the Guardian. Naturally, many people have theorized that the Guardian must be in hiding as no body was found. With that...yeah, I agree that his abandoned shades doesn't indicate that he is dead, but I also feel that it adds credentials to Aku's claim of destroying all of the time portals.
One episode left.