how do i deafeat omega pirate?

When the battle begins shoot the parts of his body that you can lock onto (which are on his shoulders and legs) until they explode. At this point he will disappear and four pirate troopers will attack you. They will either be plasma troopers, wave troopers,ice troopers or power troopers it's always random. Kill them as fast as you can (I have found that using the charge combos is the best way to quickly dispatch them) after you have killed them turn on your xray visor and look at each of the three phazon pools in the room the omega pirate will be in one of them replenishing his health. There will be a weak spot in his chest fire power missles at it until he stops regaining health. At this point he will become visible to the combat visor. Repeat this process until he has been defeated. Before you enter this boss battle be sure to search for energy tanks he can empty a full energy tank with only one hit.