Sheiny, where are the 3 Dark Torvus Bog temple keys, and how do you beat..

Here's where the 3 Dark Torvus Keys are located:

1) Dark Torvus Bog - Dark Torvus Arena: Use the Boost Ball.
2) Dark Torvus Bog - Undertemple Access: Access via the Portal from Torvus Bog - Hydrodynamo Shaft.
3) Dark Torvus Bog - Venomous Pond: Use your Grapple Beam.

Alright, fighting Chykka this is a long battle, but not too difficult!

Chykka-Larva
All this whale does is swim around in a circle while sending some flying plants at you for the first bit, then it'll jump and try and splash you with the poisonous water - make sure to follow your radar here. Finally, it'll attack you face to face. Its weak points are the belly and the top/front of the head. When it jumps up, you can hit it with a Super Missile if you're ready and quick enough, so charge up your Power Beam and use the radar! When Larva comes onto the island you're on, use the Light Beam here to do some damage.

Chykka-Adult
Once you take the whale out, get ready for round two. Keep shooting, the more hits the better - if you're good enough, you can anticipate where it's going to be (all it does is bob and weave left to right) and hit it with charged up shots. Once you've hit it enough, it will be stunned - grapple around to it's backside and use the Seeker Missile Launcher to get all 4 wings! Sometimes it'll send out some little bugs that'll give you some health and ammo while you're trying to stun it. Now, it'll get possessed by the Ing - just target it's stinger and use the Light Beam on it. Repeat this process until it's history.

Good luck - you can do it =)