How do you kill Tartarus (the brute) on the last bit of the last level..

Ok, so before you go to Tartarus, make sure you have a beam rifle with you because that's the only weapon that can take down his annoying shield. I know the marine does that also but things will go a lot quicker.

Note: when his shield is down, shoot him in the head with the beam rifle- his shield won't come back for a while and it causes major damage!

You've probably completed the game by now, but for anyone else who might be stuck, here's a non-beam rifle approach:

It's very easy to roam around the platforms avoiding the big guy. Do that until the Sergeant gets three shots in a row, and you'll see the brute's shields go down. Hit him with anything (I used some Brute Shots). Hopefully you'll hear him say something about it being a lucky shot, and that it won't happen again!

After a bit of that approach you'll be joined by a bunch of normal Brutes, and they're packing plenty of weapons. The safest thing to do is to go upstairs (if you're surrounded by them, become invisible and run to the beam lift in the center), and then pick them off with a Carbine. Once it's less crowded down there go back and start the run away, shields down, hit sequence again. If another wave of brutes comes (it did for me), go upstairs again.

At some point (it happened twice for me, so I think it happens a lot) the big guy gets pinned down by a continuous stream of Needlers hitting him. While he is stood there you can get quite close behind him, and then when the Sergeant brings the shields down you attack from behind with the energy sword. In my case I managed to get three strikes in while the shields were down, and that was enough to kill him.

To kill Tartarus, go jumping across the thing, go on the "elevator" and wait for him 2 stop (4 sum reason, he'll freeze there) and then start blasting him with whatever weapons you got.

Then he'll go up the "elevator" then retreat bak down, then repeat again if on legendary. If the brute reinforcements come, run like hell and hide, then wait for your own reinforcements 2 come, just b patient and you'll win the day. Second way 2 beat him is 2 get the banshee and fly in the broken wall (into the wall that the scarab destroyed) and fly in and go up and you'll see to holes that you can fit in and go through, and u can just blast the brutes that stand in your way! then leave your Banshee there and go throught the door (because the banshee disappears if you go throught the door with the Banshee).

When the cut scene is over, go backwards and get the Banshee and start shooting Tartarus, he'll ocassionally try jumping on your Banshee, he cant hit you with his weapon, but the brute reinforcements can! Just keep blasting Tartarus and you'll win.

Get a Banshee and go through the door that the Scarab destroyed, go up a little and youll see 2 holes that you can fit through. Kill the brutes that stand in your way, and when you do kill them, get off your Banshee and go through the door (if you go throught the door with the Banshee it'll disappear)when the cutscene is over go back to the Banshee and start shooting Tartarus, with your bombs and you'll kill him!

Knock him off the level and he dies and it also brings his life down if you didn't kill him

Try bringing a banshee with its wings blown off in to Tarturas's lair, it kinda helps.

Mate I know your pain. I'm stuck at the same bit but so far I figured out that on top of the beam rifle, the carbine will take down his shields after 1.5 clips of ammo.

Its all in my help section under Halo 2 Hints.

All you gotta do is make sure that you have a sword and some other gun to kill the other brutes, then when you gotta fight tartarus, wait for johnson to shoot him a few times and he'll lose his shield for a few seconds, while his shield is down, use the sword to kick his ass.

Dual-wield needlers always helps because if you unload both clips on him after the marine drops his shield will kill him quickly

What I ended up doing (Which killed him fairly quickly), was I used dual Needlers combined with the Bandana skull (gotta have that infinite ammo for that mofo), and I just shot needle after needle, getting supercombine after supercombine. The supercombine explosion will actually stagger Tartarus, so if you have 2 needlers, the amount of supercombines you'll get pretty much doesn't allow him to move... Until you reload of course. Pretty much shoot him until he gets to close, and when he does get too close, Camo then run to the grav lift, then jump back down when you're ready. When the additional brutes join later, I jumped down to the lower level of the area. I would wait for one to show it's head, then pump carbine ammo until it died.

You definitely need to have a beam rifle. It is the only weapon that can temporarily disable Tarturus' shields.

The sword and the shotgun are probably the most ineffective weapons because Tartarus can easily kill you if you get too close to him on Heroic or Legendary mode.

The weapons that are most effective against the Brutes are their own weapons and the Carbine.

Here is my breakdown of the effectiveness of the most effective weapons based on my experience:

Carbine: Get as many headshots as possible. This weapon allows you to stay away from Tarturus because it is quite an accurate mid-range weapon. However, the fire rate is slow and Tarturus quickly regains his shields.

Brute shot: The level of damage is likely to be high because this is basically a grenade launcher. However, it's ammunition is limited.

Brute Plasma Rifle: Dual wield two brute plasma rifles. Hold the right and left triggers as long as possible whilst Tartarus' shields are down and do not worry about overcharging the rifles. The bullets spread quite a lot so you may need to get closer to Tartarus to deal maximum damage. I think it would be better to let Johnson take care of Tarturus' shields with his beam rifle in this case.

Based on my experience, I think dual wielding two brute plasma rifles is the best option. Their fire rate is rapid and they can last for a while. These qualities are necessary to do maximum damage in a short amount of time, whilst Tarturus' shields are down, and remove the need to frequently pick up another weapon or more ammunition.

ALTERNATIVE: GET THE BANSHEE INTO THE ROOM!