|Complete "Defeat Klaww".|
Klaww's fight consists of three phases, which get progressively harder as you successfully damage Klaww. Failing to hurt him will have you repeat the current phase until you succeed.
To start with, you will be able to jump on one of any three small platforms in diamond formation, floating on lava. Falling into the lava results in instant death. Klaww will bombard you with large rocks, which are avoided by jumping to a different platform. Klaww will then change his aim, forcing you to jump back. It is important to time this properly, as the rocks do not travel too fast, though overconfidence in the slow speed will result in an accidental collision if you are not quick enough. If you jump back to a previous platform, make sure that all incoming rocks have already reached it, as it is possible to throw yourself into their path if you move too quickly.
Eventually the barrage stops, and the last rock leaves a cluster of blue eco; pick it up to activate a Precursor metal-made bridge allowing you to cross the lava and get closer to Klaww. Meanwhile, Klaww will bombard you with even larger rocks. These boulders will roll along the bridge (either along the left, middle or right). They are relatively easy to avoid and Klaww will stop once you have picked up the yellow eco cluster at the end.
Now Klaww will pause for a second or two and start to conjure a very large boulder; make sure to hit him as many times as possible while channeling yellow eco. After enough hits, he will drop it on his head (damaging him), causing the boulder to roll towards you and break the bridge. Failing to hit him enough will cause him to throw the boulder, which also breaks the bridge, forcing you to retry that phase.
If you have successfully damaged Klaww, the next phase is essentially the same, except that it lasts slightly longer and the boulders move faster. When you pick up the blue eco to activate the bridge, there will be less pieces forcing you to jump to avoid the lava below. The use of the yellow eco is identical in this stage: shoot Klaww to stop him from throwing the boulder.
The final phase is yet another repeat, but again slightly faster paced and longer lasting. There will be even less pieces left over in the bridge this time. Shoot Klaww with enough yellow eco before he has finished creating the boulder to kill him. The boulder afterwards breaks into pieces, revealing a power cell. A path to Mountain Pass will then rise up out of the lava.