Metroid Prime/Varia Suit
Chozo Ruins
Arboretum
Scan: Venom Weed
The door at the top of the room is again blocked by a gate with four runic symbols. Follow the path around the perimeter of the room. When you come to the footbridge to the tree, look across and scan the rune directly on the tree. Take the footbridge and the first platform around the tree. Facing back toward the where the footbridge connects to the path around the perimeter, if you look down, you will see a patch of Venom Weed. Blast the patch, and it will withdraw, revealing a 2nd rune. Go back to the perimeter path and proceed around the wall. Just past the sandstone blocks, and before the next rise, you will find the 3rd rune. Embedded in the tree at the top of the path, just across from the gate, is the 4th rune. Open Sesame.
To get through to the door, you must blast through a sandstone wall with a Morph Ball Bomb. Proceed to the Sunchamber.
Path: Sunchamber Lobby, Sunchamber Access, Sunchamber.
Sunchamber
Scan: Flaaghra Scan: Flaaghra Tentacle
Within this room lie many secrets, the first if which is the Varia Suit. However, first you must kill a giant poisonous water lily.
Boss Battle: Flaahgra
Flaahgra is relatively simple: it's a plant. It thrives on light. There are four mirror dishes evenly spaced about the room. Flaahgra will attempt to have at least one dish reflecting on it at all times. First there is only one dish, which you mush shoot from behind to knock away from Flaahgra. This causes the plant to faint, withdrawing it's tentacles from a bomb slot. Enter the chamber and activate the slot to wound the plant.
Flaahgra will revive and more mirrors will be aimed at it. You must knock away all mirrors before Flaahgra will faint again. It will try to prevent this by knocking back the mirrors you knock away. You can prevent this by shooting directly at the plant to stun it. This should give you enough time to get to the other mirrors before the plant resets them.
Four rounds and you are a weed killer. Take your Varia Suit. As an additional bonus, all the water will be clear from now on.