Experiment 9

Experiment 9 is the agile war machine that serves the Guardian and boss of Watergrav. Upon defeat, it drops Autodrone for Nina, or Leviathan for Ace.

Attacks
Experiment 9 has a wide variety of both melee and ranged attacks; this on top of its agility and ability to swap its own gravity at will makes it rather unpredictable. Its attacks are as follows, and are always determined randomly:


 * Throws a fan of four shuriken at the ceiling or floor (depending on its gravity), followed by a fan of three shuriken, which stick to the wall and act as small mines for a few seconds. The shuriken are not destroyable until they are stuck to a wall.
 * Throws five shuriken to each side of itself, having the same properties as the shuriken attack above
 * A divekick aimed at a random location (marked by a red ! mark) that changes its gravity, and creates an energy wave to each side of itself upon landing. Once it reaches around half HP, it will go into a frenzy and spam this attack.
 * A three-hit melee combo that moves it horizontally; the third strike will throw a single energy wave straight forward

Also, it will sometimes go to the center of the arena to perform one of two super moves on rare occasions:


 * The first super move has Experiment 9 create a large barrage of numerous energy waves to both sides of itself, rendering the surface it's currently standing on completely unsafe until the attack is over.
 * The second super move has Experiment 9 spit a huge spray of acid on the surface opposite of itself, forcing the player to go the same side that Experiment 9 is on.

Once Experiment 9 reaches a certain HP threshold, it will also spawn an Autodrone that fires directly at the player, and can be destroyed.

Finally, Experiment 9 may toss an array of shurikens onto its surface and charge up for a few moments, before forcibly swapping the player's gravity to its own.

Tips
Upon entering the arena, the player will be forced into reverse gravity by the Gravity Zone; the only way to return to normal gravity is the other Gravity Zone on the other side of the arena.

Nina is far better suited to fighting Experiment 9 than Ace, especially due to the sheer number of Powers that can reach it safely without having to run to the other side of the arena to swap gravity (Jagged Bolt, Rending Whirl, Aiming Gear, and Zen Mortar are all good for fighting this boss).

However, although Ace has a much harder time with this fight than Nina, if you have obtained Raijin Call from Hoot Omega it will make this fight much easier due to having good vertical reach.

Be careful if you're bringing an Orbital Guardian to the fight. Although the Repro will block Experiment 9's shuriken, it will still linger in the air as a mine unexpectedly. Other defensive options (such as NIna's Negation Pulse or Ace's Echo Shell) do not seem to have this problem.

Trivia

 * An early design for Experiment 9 can be seen with arms in a batch of concept art tweeted by 30XX's character artist, Glauber Kotaki. The arms were removed during the design process "to give real focus on the tail and legs, and lore-wise to show incompleteness; they're still an experiment".
 * Experiment 9 has a complete running animation in its spritesheet; however, it goes unused.