This self-explanatory mechanism serves as the boss of the North Crater Citadel near the ending of Jak and Daxter: The Precursor Legacy VII. Although previous bosses might have had tried a few different strategies throughout the battles, this boss has three distinctly different phases. If you lose on one phase, you have to start the whole fight over, so be vigilant!
Phase One: Top of the Processor
The fight starts in an arena where the boss takes up the entire center and Jak and Daxter have to run around the rim, backed up against the circular wall. This fight is vaguely similar to the Lurker Ivy boss from long ago, but this time there is only one weakpoint which can be hit- a red eye on the end of a metal wire that comes from inside the processor. This phase of the boss attacks by shooting explosive, gaseous blobs of Dark Eco out from over the edge of the open processor. Some of these blobs may leave behind Blue Eco. Use these on the launchers to shoot up and over the center of the room. Be sure to hit the red eye for big damage as you do so, but don't fall into the processor or it's all over! After this attack, it will lash out with the wire like a mace, using the spikes on the end as a sort of flail. Repeat this three times and the processor will destroy the floor, causing Jak and Daxter to topple down to the next level.
Phase Two: Processor Core
Now there is only half of the floor that there was before, but fortunately what's left is completely in one piece. This time, the flailing eye can lash out in a wide sweep at any given moment, so prepare to jump over it. It also remains spiky the entire time, so it is now invulnerable to physical attacks, having learned its lesson from the previous phase. The eye can also fire off a single, but powerful explosive shot at you whenever it feels like it. What you should really worry about this time around is a new laser attack that the processor uses. When you see a blue glow from the processor, prepare to dodge in any direction because a ton of blue laser beams will fire out at the same time for a brief instant. One of these lasers will be yellow and will leave behind Yellow Eco, which you can briefly use to damage the red eye. After enough hits, the processor will destroy the floor, sending Jak and Daxter down to the final level.
Phase Three: Processor Base
Now there is only 1/4 the amount of floorspace that there was at the beginning of the fight, still all in one piece though. The base of the processor is outfitted with the most dangerous defensive mechanisms yet- two enormous bludgeoning iron tentacle claws, and a massive central gatling cannon. The tentacle claws can only reach so far, so they'll only be threatening if you start moving forwards from the back of the wall (although after this phase starts taking damage, they'll start throwing boulders at you). However, the gatling cannon is ruthless and it can fire from anywhere at any time. Once you see it charging up, prepare to dodge a prolonged frenzy of explosive shots. Occasionally, the red eye from before will attempt to fire at you with the single-shot explosive blast from before, but this time it leaves behind a lot of Red Eco. Use this Red Eco to damage the eye- it's only thing that'll penetrate its spiny defenses. After this phase, the battle will end.
This fight will net you the 150th and final Power Cell in the game! But there is still one more task that remains- preventing Gol and Maia from opening The Dark Eco Silos.