Yeah Season 5 was largely wrote around Ashi, but I don't think her being a daughter of Aku or being able to make a time portal is too contrived in the sense it got a decent set up. She mostly felt like a plot device, but from Ep1 she was a daughter of Aku and nothing about that felt out of place.
I think one thing that I don't see enough people mention is Jack just giving up his sword immediately after he got it back so Ashi can capture him. That seemed contrived in the sense Jack didn't need to give up his sword in order to not kill Ashi. >Ashi knowing how to use a portal instantly seemed like a convenient deus ex machina to me
I don't think so man. I'm not saying I liked it and I'm not trying to be this SJ defender, I wasn't even too fond of the finale but the setup was all there man. She's a daughter of Aku, she had his powers, she used them under the corrupt state, got control of them and used them for good.
Sure, it's incredibly convenient Jack fell in love with the 1 girl capable of making his goal a reality, but again, the setup was all there. It's not like she came out of nowhere, made a portal and they fell in love. >Ashi doesn't even know what era Jack comes from
I mean, it's possible Jack told her, but I think concerns like how does she know how to create a time portal and where to send it, as well as use laser eyes seems like it's more to do with how Aku's shit works, and we don't really know that. Personally, I don't see a big issue with "I can do it too!", because Aku did awaken the "Aku inside of her" and whatever.