Kalidus Channel is divided into two parts. The reason why is that more than half of the level is underwater, but you can't go there until you have a certain relic and enter through another way. Because you don't have the required relic, if you jump in the water, you'll just float. Focus on jumping between boxes and rocks attacking all the enemies that gets in your way.
Saving the first Villager: Jacob
About halfway you'll find another man frozen in a large crystal with the Torpor glyph above him and a Magical Ticket next to him. Absorb the glyph to free Jacob. Although he doesn't give you side quests, he runs a shop where you can buy and sell items. Now with him saved, continue right and save at the save point. Then keep on going until you reach the water again. Immediately above is a breakable wall that contains a hidden Twinbee. Keep going right to leave the dungeon.
Back at the travel map, the blackened icon is now revealed. You can now go to Minera Prison Island. Go back to Wygol Village to save and buy anything needed in the newly opened shop. When ready, go to Minera Prison Island.