Can anyone help me with the desert missions? I got Elona done.
Good for you - a lot of people get stuck on Elona because they have no clue.
Dunes of Despair is trivially easy. Just do it with henchmen. Ignore the Siege Wurms, stay close to the Hero and keep an eye out - no worries.
Thirsty River can be tough if you don't know what you're doing, but with a semi-decent party it's not too hard. The trick is to time your runs, and to kill the bosses in the right order.
In the second area (the one with two bosses), run straight ahead at the start - nobody go right or aggro any packs there. Kill the pack outside, then go into the Temple and take out the Priest. Once he's dead the rest of the pack won't respawn, so get everyone inside the temple and kill the bad guys. Then head outside and wait for a time 15 seconds before a two-minute breakpoint (1:45, 3:45 etc). Timed right, you won't kill an enemy before the clock rolls over the breakpoint and so you'll have two full minutes to wipe out the guards and the Priest.
The last area has three bosses, which is tougher but oddly also easier. As soon as you start, turn right and
run the entire party straight into the first Temple - ignore the guards. Kill the Priest, then hole up in the Temple killing things. After that it's the same as before - wait for 2x+1:45, then charge into the Temple and kill the Priest.
The last boss is tricker, because he's a Monk boss. Kill the party of guards outside, then head into the Temple. This time, though, you want to have some of the party attack the boss instead of all piling on the Priest. You do this to make the boss heal himself instead of the Priest, making it easier to kill the Priest. Once the Priest is dead, kill the boss.
Also, if you're a Ranger, Warrior or a Monk you should bring a Signet of Capture on this mission. The Mesmer and Necro elites are naff and the Ele elite has been nerfed, but Word of Healing is the single best healing spell in the game and the Warrior and Ranger elites are both excellent energy management skills.