Sucy makes a magical potion that is supposed to increase magical ability. She drinks it then falls into a deep sleep, Sleeping Witch Sickness. To cure it Akko has to go into Sucy’s mind and wake her up.
I felt like this episode was homage-ing Spirited Away and Disney’s Sleeping Beauty.
Also I definitely felt like my chain was yanked throughout. Especially with the: was it all a dream? ending.
And yet, I still really liked it overall.