On to some real challenges! But first, a word from our sponsor.
You're still in the Burn Dome, and it isn't quite completed yet. There's an oddly patterned ditch cut into the floor. At one end is a piece of wall with "structural weaknesses." Translation: bomb it with your new bombs. The Chozo have provided you with a complimentary Missile Expansion. We knew you'd be pleased.
Proceed back to the Energy Core via Burn Dome Access. We need to finish that puzzle.
Energy Core
Scan:Morph Ball Slot
To your left is your first Stone Toad. They are totally impregnable except from within. They also have an insatiable appetite for 1-meter spheroids. If you happen to have the Morph Ball Bomb, they're easy pickings. If you were thoughtless enough to play with them before you got the bombs, it was the end of the line for you, wasn't it? At any rate, now is the time to get eaten. Morph down and present yourself to the Stone Toad. Once consumed, drop the bomb. Presto: open path.
In the inner chamber, is a Morph Ball Slot. Activating this slot will lower the water level in the main room. Exit the room through the hole in the window, and enter the (newly exposed) inner room at the ground level. Here you will find an identical Morph Ball Slot. Activating this slot will raise the platforms in the room, providing a path to the third chamber. Identical. Activate the slot, raising another set of platforms, and unlocking the far door. The entire process is timed. Complete everything and you'll never have to do it again.
Proceed to the Furnace via the West Furnace access.
Furnace
Two roads diverge in this room, and you - you take the one less magnetized. Especially since you haven't got the Spider ball, and therefore can't. At the end of the tunnel is an Energy Tank.
It's also the end of the line. We need to head back to the Arboretum to work toward the Varia Suit, but first we want to take a small detour at the Watery Hall again, since there's a bit more of a way open now that you have the Morph Ball Bomb.
Path: Burn Dome Access, Energy Core, Energy Core Access (short cut with Morph Ball Bombs!), East Atrium, Gathering Hall, Save Station 2, Gathering Hall, Watery Hall Access, Watery Hall.
Watery Hall
In the Watery Hall, follow the raised platforms to the far end of the room, where the Chozo Lore plaque is. You will find a hole that can be opened with a Morph Ball Bomb. Open it and proceed to the Dynamo via the Dynamo Access.
Dynamo
There is only one thin you can get in this room right now: a missile expansion in a small alcove blocked by a metal grate. Blast the grate with a missile and get your prize.
Proceed to the Arboretum. Path: Dynamo Access, Watery Hall, Watery Hall Access, Gathering Hall, Gathering Hall Access, Arboretum
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
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.