Helios is the guardian of Elysia's Leviathan. This machine looks like a small round sphere with four tentacle-arm like appendages. He is the prime robot of a group of Swarmbots, also inhabiting the Leviathan. Helios has seven forms. All but the final form are invulnerable, and he only takes this form after being stunned in any of his other forms many times.
The first form he appears in is his neutral form. This form is surrounded by a large sphere of Swarmbots acting as a shield. He will float in the middle of the arena. He may change into any of these:
Bowling Ball: After arranging the Swarmbots into a large sphere, he will fall to the ground and try to roll toward Samus, who can get out of the way and fire at the core in between the Swarmbots.
Disc: He will arrange the Swarmbots into a large disc which has five weak points. These must be shot all at once with the Seeker Missiles. If he remains in this form for an extended period of time, the disc will increase in size, making it harder to dodge. The disc can also charge up and fire a large beam of Phazon.
Beam Array: He will arrange the Swarmbots into many small groups that will in turn charge up and fire at Samus. The glowing groups can be destroyed before they fire.
Tornado: He will arrange the Swarmbots into a large tornado with himself at the base and start spinning toward Samus, sucking her towards inwards to deal contact damage. Morph Ball Bombs and the Hyper Ball can strike this form.
Humanoid: Helios will split the Swarmbots into four groups which will become "arms" and "legs". These will sometimes hurl giant orbs (that create a small, horizontal explosion) at Samus. The legs also can make a powerful shockwave. The joints at which the limbs are connected can only be damaged when the corresponding limb is preparing to attack; once Samus destroys each of these joints, Helios will collapse.
Exposed: Once he has been hit enough in the previous forms, he will open his core and dispel his Swarmbot backup. His mechanical arms will extend blades and he will charge repeatedly at Samus, who must go into Hypermode and fire her Hyper Beam into the front of his core to deal damage to the mechanoid.
- "Helios's exterior armor is well shielded, but still vulnerable to Beam weaponry. Inflicting enough damage will cause him to overheat and expose his Phazon-enhanced core. This core can be overloaded with Phazon-based energy. Destruction of the core unit should prove fatal, but is difficult to achieve. Target is the prime bot of a large group of Swarmbots, all of which have been energized by Phazon. Helios will use the Swarmbots for both offensive and defensive measures. Assuming different formations will allow for various forms of attack." — Logbook "Helios" (Metroid Prime 3: Corruption)