Elemental Fury is the 9th side mission.
Bring a soldier with a high damage weapon or a weapon with a fast rate of fire as the Elites can quickly overwhelm your defenses, especially if they have DSR1 or Rail Gun as these have high accuracy. Engineers and Mercenaries with explosives (such as Bennett's Doom, Tank Buster, etc.) are generally the best choice. Juggernauts will also work. However, it is recommended to bring a long-ranged shotgun as you will probably get killed first. You can also use classical sniping on high platforms if all Elites are on the ground.
Normal: Elite class