ok - FIRST, you will need around 100-ish missiles. SECOND, at least 3 quarters of your total extra energy tanks (the squres above your life metre). THIRD, you will have to be brave enough to face (in my opinion) a boss that is a bigger son-of-a-b**ch than all the rest! OK! Firstly SCAN HIM! Always do this! Shoot the Phazon off his legs and arms, i find the Plasma Beam is the best here. Strafe around him before u get backed up against walls. When you've taken all the Phazon off him he'll become invisible. Switch to your X-ray visor, and Power Beam. He'll appear in one of the three Phazon pools in the room. Him hit him in the chest with a Super Missile as many times as possible before he recovers. !!!IGNORE THE 3 PIRATE TROOPERS WHO ATTACK, IF YOU TRY & KILL THEM YOU WIL RUN OUT OF TIME TO GET THE OMEGA!!! the omega will kill them with his attacks! (this is why you need plenty of energy tanks!) repeat the above untill you bring the git down!
Plz rate!

its actually quite simple make sure u hav about 8 energy tanks nd bout 120-200 missiles. if u used som missiles or not at full energy, go bak to the reload nd save stations.

1. Approach the tank slowly with the scan visor cuz u can scan him while he's sleeping.

2. Use either the plasma beam or super missiles to destroy the phazon armor on his arms nd legs. dont shoot him when he has his hand out nd its glowing yellow. also be aware of your surroundings cuz u dont wanna run into phazon cuz its everywhere. And dont get too close to him other wise he'll hit u with his hands. if ur cornered, go to ball mode nd boost ball away.

3. He'll turn invisble, calling in power/wave/ice/plasma troopers to attack u which is good cuz they're alotta easier to kill nd they giv u energy. Beat them quickly nd use the X-ray visor to find him nd shoot him with the super missile cuz u only get one shot at him then he disappears. Also b quick about it cuz if u go slow, he'll recover some health nd u'll miss ur chance to attack him.

4. Repeat 2-3 until he dies. once u kill him, he'll fall on u nd u'll get the phazon suit nd beam.

i'm not sre there is an EASY way to beat him

yea he is a tough mother...even harder than ridley or metriod prime...