use the hm flash which is given by sage at the top of sprout tower
with the HM: flash To light up every dark cave
You don't. That's only in the original Pokemon Mystery Dungeons. Red and Blue version
use their Pokemon
The Cave of Origin is in Sootopolis
you can use it in any cave to get out of the cave
unfortunately, there is no location called "chlorine cave" in Pokemon leaf green version
Mewtwo lives in cryptic cave, you can get Cryptic cave from wigglytuff in the Pokemon square.
yes
there is none!
mistralton cave
Unknown Dungeon was the name of a cave in Red, Blue and Yellow version that is located northwest of Cerulean City you would need Surf to reach their the cave is now called Cerulean Cave.
You Can Go Into This Cave Once You Have Beaten The Pokemon League. Cerulean Cave Is Where Chanseys And Mewto At LVL 70.
Mistralton cave