Don't clear your terminal history 4

Question

Previously, on terminal use...

A panel raises into the wall, revealing a hallway and the outline of a sword. "Must have been taken already", you figure. You walk down the hallway and enter some kind of control room. There are 3 large lights illuminating the room. From left to right, they are colored blue, red, and green. There is a circular table in the center of the room that has a full world map designed on it. Scattered around the table are various maps of different countries on the planet. On the far wall is a large terminal, spanning the length of the entire room and stretching towards the ceiling. On the screen you see the following:

> SNIYN
Access granted. Door opened.
> OSCJC
Access granted. Door opened.
> HUGUNGJ
Access granted. Door opened.
> RMLLKQK
Access granted. Door opened.
> MOWYNRHLFTY
Access granted. Door opened.
> PDRGS
Access granted. Door opened.
> 

A keyboard slides out as you approach...

Hint

After looking around the room a while, you notice there are some faint designs in the lights. The design is a circle with a much smaller circle perfectly in the center and a line crossing through the middle of both.

Inside the smaller circle in each light is a number. The blue light has a 7, the red light has a 4, and the green light has a 1

Each map also has a 90™ in the top left corner.

Hint 2

Upon closer inspection of the maps, you notice that the colors used for the various markings on each are different. Among other options, one map has blue and red, another uses black and white, and another seems to have a silver and gold system.

Hint 3

Feeling there must be something you've overlooked, you check every inch of the room for any additional clues. Behind the terminal, you notice a sliver of paper. It reads, "I am the first one to come through here. In the event that you get stuck, I hope my card will assist you. It is kind of old and scratched up, but if you've made it this far I'm positive you can understand it."

Answer 1

Ok, all entries are substitution cyphers for the real live equivalents of capital cities of pokemon regions with the first mythical pokemon of each region as the key:

SNIYN = Tokyo (Region Kanto = Kanto, key Mew)

OSCJC = Osaka(Region Johto = Kansai, key Celebi)

HUGUNGJ = Fukuoka (Region Hoenn = Kyushu, key Jirachi)

RMLLKQK = Sapporo (Region Sinnoh = Hokkaido, key Manaphy)

MOWYNRHLFTY = NewYorkCity (Region Unova = New York, key Keldeo)

PDRGS = Paris (Region Kalos = France, key Diancie)

The correct answer is the capital of Gen 7s region (Alola) in real live (Hawaii) which is Honolulu. Using the key Magearna (first mythical Pokemon of that region) we arrive at

CLKLIUIU

Answer 2

Partial answer

All of this seems to be about Pokemon.
- Small circle inside big circle with line in the middle is a Pokeball.
- The hints also refer to the multiple generations of Pokemon games. Red and blue = generation 1, silver and gold is generation 2, black and white is generation 5.
- "tm"s are skills you teach to your Pokemon and there all come with a number depending on the skill.
- The 3 lights could possibly refer to the 3 usual starter Pokemons (fire, water, grass)
- The various maps could refer to the maps in the game. Like johto and kanto.
- The number 1,4,7 probably refer to pokemon index in pokedex.
-- 1 probably bulbazor(green starter pokemon, index 2 and 3 being its evolution)
-- 4 being charmender(red starter pokemon, index 5 and 6 being its evolutions)
-- 7 being squirtle(blue starter pokemon, index 8 and 9 being its evolution)
-- as for the tm 90 skill, the number and skill associated with them change in each generations, but in one of them it refers to the skill substitute, which is probably a hint that we must substitute letters to find the cipher.

UPDATE

There is currently 7 generations of pokemon and 6 answers already given, so quite likely 1 for each generation. Each generation have a main map.
1 = Kanto
2 = Johto
3 = Hoenn
4 = Sinnoh
5 = Unova
6 = Kalos
7 = Alola
Unfortunately, the number and patern of letters cannot be matched to the current cipher with just a normal substitution algorithm.
The system in pokemon is not countries but regions. The question says "maps of different countries on the planet". Combined with the fact that there is a geography tag, it really feels like we need to make a connection with real world countries somewhere but still cannot find the connection.

NOTE

I haven't played those games in over 15 years and only played the first generation so please forgive my possible lack/erroneous knowledge ;P

UPDATE 2

It appears to be a list of encrypted capitals of various countries.
The goal is probably to decrypt all of them, find the relation between them to guess the next one and then we must also find how the next encryption key is decided to encrypt the answer before entering it.
Here is what I could find until now using a simple substitution algorithm with a key.
________________________________
SNIYN -> Tokyo
Keyword : mew
ABCDEFGHIJKLMNOPQRSTUVWXYZ
MEWABCDFGHIJKLNOPQRSTUVXYZ
________________________________
PDRGS -> Paris
Keyword : dhaka(Captial of Bangladesh)
ABCDEFGHIJKLMNOPQRSTUVWXYZ
DHAKBCEFGIJLMNOPQRSTUVWXYZ
(We don't write the last A because duplicate letters must be ignored.)
This one was probably a very very very lucky guess and might not be the correct key. ________________________________
OSCJC ->
Judging by the word length and the repetition of the C I suspect this to be Dhaka or maybe Kyoto(not a capital anymore)
________________________________

Answer 3

Building from stack reader's uncovering of the cipher method:

(Which is a keyed substitution cipher)

We get for the six known entries:

SNIYN: TOKYO, key Mew
OSCJC: OSAKA, key Celebi
HUGUNGJ: FUKUOKA, key Jirachi
RMLLKQK: SAPPORO, key Manaphy
MOWYNRHLFTY: NEWYORKCITY, key Keldeo
PDRGS: PARIS, key Diancie

But I still don't know what the seventh entry would be...

Answer 4

Continuing on from and clarifying @stack reader's very good partial answer:

The lights each correspond to a Kanto starter Pokemon: blue is Squirtle (Pokedex No. 007, Water-type), red is Charmander (Pokedex No. 004, Fire-type), green is Bulbasaur (Pokedex No. 001, Grass-type).

Each map corresponds to a specific Pokemon generation (Red/Blue is Gen 1, Gold/Silver is Gen 2, Black/White is Gen 5, presumably there are maps corresponding to the other generations as well). I am assuming, however, that the maps are of real-world countries.

I am therefore assuming that the scrambled letters on the screen correspond to either the names or capital cities of real-world countries, scrambled using a substitution cipher ("90™" = TM90 = Substitute, as @stack reader suggested).

UPDATE 1: I believe the cipher for the first string relates to Gen 1 somehow, the cipher for the second relates to Gen 2 somehow, and so on, so to get the answer, we will need a cipher related to Gen 7. I shall investigate further.