Unknown Cell-046 is a large mass of green ooze that houses five purple nuclei.
Unknown Cell-046 appears as the mid-boss of Immigration Ship L-229. Defeating it grants the Burn Spark Sub-weapon, allowing Gaia-SOPHIA to perform an invincible dash while on fire, to destroy the barriers on the ship, and to disable Defend Them All's shield.
Unknown Cell-046 starts the battle by oozing out from the wall at the top of the arena. As it slowly moves down, nuclei will begin to appear, denoted by a sound that plays. There will be five nuclei in total, and they will move with the ooze until the entire room is filled, although they slow down as they get closer to the end of the room. Once all five nuclei are dispatched, the ooze will retreat, and it will reappear from one of the other walls (excluding the bottom one). The nuclei will occasionally fire projectiles at the player as well. Sometimes, ooze will appear from both the right and left walls, with three nuclei on the right and two on the left. When at low health, the nuclei will start moving perpendicular to the direction the ooze is moving.
|“||If the enemy reaches my foothold, I'm done for. Gotta do everything I can to keep it at bay!”|
The Unknown Cell-046 fight lasts 8 "rounds". For the first three rounds, Unknown Cell-046 will emerge from the top, right, and left sides once, in no specific order. During the first round, it will only ooze out from one of the walls in an attempt to cover the entire arena; after the first round, the nuclei will begin to fire projectiles at the player and can be targeted with Blast Counters just before they shoot. During the fourth round, three nuclei will appear from the right and two from the left; the right side will only cover 3/5 of the arena, and the left side only 2/5 of the arena (or vice versa), so if one side is destroyed, the player will have space to deal with the other. During the eighth round, the nuclei will begin to move around.
Whenever a nucleus is destroyed, it will drop an Ammo Capsule, allowing the pilot (Jason, Copen or Empress) to make liberal use of their sub-weapons. No health or Gun capsules can be obtained during the fight.
Unknown Cell-046 is rematched on Planetoid G-3, where the fight plays out identically. If Jason enters either fight while in possession of the Torch Bomb sub-weapon, he can use fire-element attacks (Torch Bombs or fire-enhanced G-Blaster/Splasher/EX Charge shots) to set the boss on fire, causing the entire tide of ooze to dissipate except for a small puddle around each nucleus in the wave. Nuclei which are reduced to this puddle state will attempt to flee off-screen and reform into another ooze tide. (For waves in which the boss approaches from two sides, two ignitions, one for each side, must be inflicted to fully dissipate the ooze tide.)