boss tricks: gandrayda
Gandrayda can be defeated in well under a minute with screw attack. Most of her movements are random, however, so it takes at least as much luck as it does good timing. The next few paragraphs will try to serve as a general guide, covering what she does most often and the things that are important to know.
Gandrayda will always go left first, and you can hit her if you immediately turn left a bit and screw attack forward. She continues going left for a while, and you can hit her again if you time the activation as she jumps into the air, but it's a lot harder than the first screw attack. Two hits usually triggers the cutscene (only one if you're lucky).
After the cutscene, Gandrayda will almost always jump right at you. Screw attack forward to hit her, and try to get her a second time before she moves away. Again, two hits is often enough to get her down to the last third of health, but you do have time for one or two more screw attacks. Any longer and she turns into Rundas, and it's over when that happens.
Gandrayda will use her Samus form after the cutscene, boosting around the room. Go hyper and charge a shot while tracking her, releasing it when she unmorphs. Try not to be close when she does or she'll put up a forcefield and go back to boosting. If she starts running, that means she's about to leave the Samus form. Exit hyper mode and stay close, waiting to see her next move. The next phase is the least predictable; be sure to take advantage of any grab attempts, as they leave her open to attack. She always stops moving and looks at you before trying it.