Boost Guardian

The Boost Guardian, also known as the Boost Ball Guardian, is a Warrior Ing that had absorbed Samus' Boost Ball and subsequently mutated in Metroid Prime 2: Echoes. The Boost Guardian is found in the Dark Torvus Arena.

Battle
The Boost Guardian has several different attacks. It has the typical abilities expected of a Warrior Ing -- slashing, possession, energy beams, and amorphous transformation. In addition, it can also summon Inglets while in puddle form and boost around the room in the form of a spherical ball. In this latter attack, it can destroy any of the four pillars within the arena as well as any Inglet with which it comes into contact.

There are two phases within the battle, the first fighting it as a regular Ing and in its Boost Ball. While in the second phase, the Ing will constantly boost around the room and move about as a puddle. During this time, the Guardian is only vulnerable to Morph Ball Bombs, but immune to any damage. After some point, it will return to phase one.

Logbook entry




Trivia

 * After defeating the Boost Guardian and getting the Boost Ball, the pillars in the room can be destroyed.
 * Due to the lack of space in the room, the small amount of obtainable energy tanks before the battle, the high velocity of the Boost Guardian's Morph Ball form, the mass damage of its Boost Ball (approximately 50 units with the Dark Suit and 100 with Varia in the GC version, yet toned down in the PAL and Wii versions), the lack of light crystals and light beacons, and the space taken up by the puddle forms of the Boost Guardian and the Inglets, the Boost Guardian can be considered to be one of the most difficult bosses in Metroid Prime 2: Echoes.
 * The Boost Guardian is identical in appearance to the Jump Guardian.
 * Both the Boost Guardian and Jump Guardian are the only Sub-Guardian bosses that fought Samus in their Ing forms; that is, without possessing another creature.
 * Senior director of development at Retro Studios, Bryan Walker, claims that he was never able to defeat the Boost Guardian without going into debug mode.