Samus' eventual Phazon corruption doesn't come without its benefits. Thanks to her Phazon Enhancement Device (PED) Suit, Samus can tap into her body's Phazon reserves and utilise the substance as a potent energy source.
While Hypermode is active Samus is completely invulnerable and can deliver strong blasts of Phazon more powerful than her regular projectiles. There are, however, potential risks in utilising this dangerous technology.
To enter Hypermode, hold the Plus Button. Your view will switch to a greyscale depiction of the surrounding area while a solid white bar appears at the top of the screen. The "Energy Tank Injected" message refers to the utilisation of one of your Energy Tanks to power Hypermode, so don't go wasting health by using Hypermode too much.
Hold the Plus Button again to exit Hypermode. Upon reverting to normal you'll lose however much energy you spent while in Hypermode from that one Energy Tank (up to 100 points if you used it all).
Initially you'll begin with a standard Phazon attack for your arm cannon, but will eventually acquire new forms of weaponry. Each blast of Phazon energy from your weapons will drain your Phazon meter, once the meter empties you'll automatically return to normal mode.
Early in the game Hypermode will also automatically disengage after twenty-five seconds of use. You may also find yourself shunted out of Hypermode prematurely from certain enemy attacks and hazardous environments such as Fuel Gel pools (without the Hazard Shield equipped). See below for a quick summary of Phazon attack forms.
Eventually Samus will find herself entering Corrupt Hypermode later in the game, usually by remaining in Hypermode for more than ten seconds. Two signs will tell you if this happens, one, you can't manually switch off Hypermode, and two, the white Phazon meter will change to red. In this state the Phazon levels in Samus' body begin climbing to critical levels - you'll notice the red bar will slowly increase. Allow that bar to fill up completely and her visor HUD will flash red and yellow. Stay like this for a few more seconds and Samus will become utterly corrupted, ending your game right there and then.
Thankfully some quick reflexes will ensure that never happens. Watch the white Phazon meter, if it ever turns red simply blast away at anything and everything to vent Phazon energy from Samus. Drain the bar to return her to normal and out of danger. If you remain in Corrupt Hypermode and regulate the increasing Phazon levels (a good tactic to prolong the use of Hypermode), eventually the PED Suit will automatically drop Samus out of Hypermode after twenty-five seconds (don't be scared by the gradually cascading alarm sound, all it means is that her suit is about to auto-vent Phazon).
If you sustain damage while in Corrupt Hypermode the red energy bar will increase dramatically. Oddly, this can be used as an effective tactic to quickly give yourself more Phazon energy while in the middle of a firefight, instead of waiting for it to slowly rise (just keep firing to make sure the bar doesn't max out). Also be wary of certain Space Pirate foes; if they throw a grenade near you the blast will send you straight into Corrupt Hypermode - don't waste any time venting energy. On the upside, if a grenade sends you into Corrupt Hypermode you won't lose an Energy Tank as per normal, so use the Phazon firepower for as long as possible.