You arrive at Unimatrix Zero with your team mates. You find massive Borg structures, including a Diamond where the Borg Queen has transferred her Conciousness to.
This mission is a lot of fun but is the toughest out of all the Borg STF's in space.
Defeat the Queen's Guard. They will be surrounding her Diamond. It is optional to do this in 10 minutes. Normally this will consist of around 6 Cubes and some Sphere's in this mode. The best method is take the Cubes out one by one as more that come in are likely to defeat you and your team.
There will be a cutscene. There will be 2 very large and dangerous Unimatrix ships that will warp into the system. They will park themselves on either side on the Borg Diamond. Stay at least 5km away from them to try and avoid Lance fire from them (believe me these hurt)! If you hover near the Borg Diamond you have a better chance of avoiding the Lances. The best method is for the team to focus on one at a time. Never go behind the ships as these tend to be where the Lance comes out of and fire those massive high yield plasma torpedoes. The optional is to keep 3 player's alive. Even in Normal mode this is difficult to achieve.
Once both ships have been destroyed, the Diamond with the Borg Queen will activate and you'll need to fight it. This fight will be challenging as the Queen likes to throw abilities at you, such as Scramble Sensors making you fire at your team mates! Her Feedback Pulse is also quite deadly. The Diamond has a very high Hull count and it will take some time to defeat it. Keep firing and throwing everything you have at her until she is destroyed.
HINTS AND TIPS:
Tanking builds are more suited for this one.
When firing on the Cubes in stage 1 its good to shoot them - Top-Down.
Do not linger around the Unimatrix vessel's. Stay around the shielded Diamond.
The Borg's High Yield Plasma Torpedoes kill in one shot. I have seen some really heavy Tank builds take the brunt and be defeated. The same applies to the Lance Weapons.
If one of the Unimatrix ships has not been destroyed by the time Re-generation probes come out, the fight will be more difficult.
Advanced and Elite difficulties will me much tougher so be prepared to face the fire.