Leviathan Abyss

The Leviathan Abyss is a location in the combat map screen. It consists of 4 sections, each section contains a series of stages that are categorized as depths, ranging from 1000m to 9000m. It is the area where players can gain a lot resources such as BP, Flow Solutions, Nano Neuro Parts and Equipment Parts every day.

Mechanics
The Leviathan Abyss has a limit on the amount of challenges to do at any time. The maximum limit the player can challenge any stage is 6 times. Challenge recovers once every 4 hours. New players will gain 12 challenges upon visiting the Leviathan Abyss for the first time.

The stages of the Leviathan Abyss contains 3 waves and are composed entirely of Dolls, many of which uses similar strategy to the player such as using Heavy Cruisers at the front, Destroyers and Light Cruisers at the middle and Aircraft Carrier at the rear.

Also, each stage has 3 conditions:
 * Win within 160 seconds with 5 dolls surviving
 * Win within 220 seconds with 3 or more Dolls surviving
 * Win within 270 seconds with 2 or more Dolls surviving

A letter grade is given based on how many conditions has been completed. This ranges from N, if no conditions have been completed, to S, if all conditions have been completed. The current stage must have a grade of S in order to proceed to the next stage.