>>89808619>They're honestly going to have to retcon this episode out of existence.
It's really just shit writing, call it what it is.
Adventure Time handled this better in Puhoy. Finn just forgot everything, and returned to his normal self by the end of the episode. People might have whined about always returning status quo, but you can't do crazy episodes and actually have them matter.
Marco having lasting effects (the mark, the scissors) and being mentally 30 sounds daring in concept, but only if they commit to it. And this show isn't plot-heavy enough to try it. They're just going to pretend it never happened or lampshade it, probably the latter because the scissors will have to get used eventually.
The litmus test is how they handle his old relationship with Jackie. He spent so much time fighting Heckapoo that they're friendly with each other, her demeanor changed from condescending to seductive, and he trusts her enough to leave his motodragon familiar with her. They even pulled some scene fuckery like pic related.
When he got back, all the visual cues in >>89808854
indicate that his experiences have lasted, and he comes off as distant from his old mundane life that he left behind. If he's also distant from Jackie, then they might actually be committing to the 16 year gap in time.
But odds are high that this was just a non-canon gag episode. Non-canon in that it will never come up again and won't have a lasting impact on the characters mentally, but canon in that the scissors will still physically be there, which will remind people that it happened. That's just part of the shit writing.