Fast forwart to the beginning of the final season. Finn FINALLY gets more time with Huntress Wizard, and gets to see if she's better now. Problem is that in the previous season, he ended up killing someone to save his own life, and that really fucked with his head. He was pretty much forced to hunt & kill a monster while harboring a "all killing of any kind is wrong" mentality, and that shit was not going to fly. Long story short: Huntress Wizard gave him a lesson that could be summarized as "Is it still wrong when other people's lives are on the line? Is it wrong if it's MY life on the line?" That pulled him out of that mentality, and HW immediately starts to seduce him and we get pic related. It definitely seems she sorted some of that shit out and is actually ready for a relationship. Notice the mutual kissing action, as opposed to the awkward one-sided thing from before.
Then throughout the series, you see little acknowledgements that their relationship is totally a thing that is happening, with his 17th birthday episode showing it the most. The most notable change about her is that she abandons that toughgirl voice and the result is adorable as fuck. Then, for some retarded reason, the finale didn't even acknowledge it, even though they didn't have a falling out or anything like that. There was certainly other more important shit going on, but it was bullshit to leave that end loose like that, ESPECIALLY when Finn's love life has been a key ploy point several times throughout the series.