SOLUTION: THE KEYCARD SCANNERANSWER: SHUFFLE THE HOLODECK
Feeder answers:
DUST STORM
FOLK SONG
FREE FLOAT
HEAD LOCK
HEAT SHIELD
SINE WAVE
SLAP DASH
SOFT VOICE
STAY SILENT
In this round, solvers are given a card upon solving each puzzle; the cards don't correspond to the puzzles they are obtained in, however. Each card has an icon in its center relating to the theme of one of the other puzzles. Each card has four empty squares at the top, which allows the first word of the feeder entry corresponding to that card to be entered into those squares (as all of the feeder answers begin with a four-letter word). The second word of each feeder can be written into the empty rectangle at the bottom of the card. After doing this, the cards can be arranged in a 3x3 square such that letters in squares connected by lines are identical:
Once the cards are assembled, the given numbers in the upper part of the metapuzzle page can be used to index into the second words of the corresponding feeder answers. In western reading order, these letters spell CLOW CARDS; searching for this phrase reveals another commonality between the answers: the second word of each feeder answer is the name of one of the Clow Cards from the manga/anime series Cardcaptor Sakura; as an additional confirmation, the Clow Cards' names are positioned at the bottom of the cards, in the same place where those words would be written on this puzzle's keycards.
This provides the ordering for the lower part of the metapuzzle page: the order that these nine cards are captured by Sakura in the anime series. (There is a separate capture order for the manga, but the manga doesn't include all of the cards used in this puzzle, disambiguating which ordering is used in the puzzle.) That ordering is:
(STAY) SILENT
(HEAT) SHIELD
(DUST) STORM
(FREE) FLOAT
(FOLK) SONG
(SLAP) DASH
(SINE) WAVE
(SOFT) VOICE
(HEAD) LOCK
Extracting the given letters and reading them off (reading the letters from all of the first words before the letters from the second words) spells out the final answer, SHUFFLE THE HOLODECK. Entering this answer takes solvers to the finale, telling solvers that they have completed the hunt.
The keycard given after each solve not corresponding to that puzzle is an attempt to adapt the way this hunt was presented to my partner: I had quickly put together a set of physical cards, sleeved them so they could safely have answers written and erased, and given a random card to my partner after each puzzle solved in this round. Since this site doesn't have any account system, there's no way to provide random cards without introducing a host of issues, so I opted to have one "random" arrangement of keycards on a set of static answer pages. There was an added benefit to having one set arrangement; I was worried solvers might think the Miku keycard would correspond to Hooked on Phonics instead of Synthetic Food, so I was able to fix that keycard to Hooked on Phonics' answer page so there would be an explicit message that that keycard did not correspond to that puzzle. In retrospect, I should have just used a spring onion or some other icon on the SINE WAVE keycard; apologies if any solvers forgot which puzzle that keycard came from and wrote SOFT VOICE on it.
This puzzle was particularly fun to set up on the website, as I found out that the animation used on the answer pages for the keycards was surprisingly easy to do with CSS; this also led to some of the animations used on the round pages, and I will absolutely be taking advantage of these CSS tricks in future hunts.