Secret Base of Cobolt in Lunia is an raid stage (8-player maximum) for level 50+ players only. It generally takes 30 to 60 minutes to complete and offers good repeatable exp and various good items. This guide is meant to show new players how to gain entry and describe the various tactics used to complete this stage quickly and safely.
Accessing the Stage
To unlock this stage, you need to beat Legend Cobolt Battlefield, which requires a Stone Carved Key from the land spirits in 3-3 to unlock. You can also have someone who has previously cleared Cobolt Battlefield open it for you with their token. Save either the Injured Cobolt or Injured Land Spirit, then complete all of their quests to unlock Secret Base of Cobolt. The side you choose to help will determine which ring you receive at the end. For more information about the two sides, see the Rewards section at the end.
To access the stage, you will also need Cobolt King's Secret Key (obtained by defeating the boss at Legend 3-4 or as a common drop from the Cobolt Captains inside the raid, used up when you pass the raid's door) or "Key to a heavy duty secret base" (obtained as a rare drop from the Cobolt Captains inside the raid, lasts forever)(Lunia Gold).
Special Tactics
Because Secret Base of Cobolt is currently our endgame and arguably the one of the more complex stages to complete or rush, a number of tactics have been developed that are especially emphasized in speed runs of this stage in order to finish quickly and safely.
Blocking
This is when someone stands in front of a mob while the rest of the party attacks from a distance. Because the mob will be targeting someone who is far away, it will attempt to chase them, but not be able to move due to the blocker. This tactic only works against enemies that will not attack when someone is on the edge of their range, and so is best used against the Black Sand Scorpion Kings and Cobolt Captains.
Down attack spamming
Probably not the best name for this, but basically, because you have 8 people, the fastest way to clear most ordinary enemies in this stage is to group them up, knock them down, and spam down attacks on them. If you really want to move quickly, this is the tactic you should use on everything that can be knocked down.