Diablo II: Lord of Destruction/Elemental

Mimicking his comrade the sorceress, a druid may cast two of the four major types of elemental damage--fire and ice--as well as spells that harness the power of wind. These skills do not require that a particular enemy monster be the intended target, and they all have the ability to do damage to multiple foes. As a result, a druid specializing in elemental arts will shine most brightly against crowds of enemies.

The most powerful elemental arts use quite a lot of mana; fortunately, among the summoning and shape-shifting disciplines are skills that allow the druid to recoup mana from enemy creatures, both alive and dead.

Firestorm
While this spell is ineffective against single opponents, especially at medium to long range, it is quite effective against crowds of enemies at close range. It needs no particular target and can be fired onto any visible piece of ground. Aim it behind oncoming groups of enemies, and the fire tendrils will snake through the group, causing damage to each creature they come in contact with.
 * Description: Sends tendrils of flame along the ground, damaging any enemies it contacts
 * Level prerequisite: 1
 * Skill prerequisite: None
 * Mouse button: Left or right

Molten Boulder
The fiery boulder created by this spell rolls from the casting druid in the direction of the attack. A creature need not be targeted, so attacking a piece of ground beyond the intended target(s) is most efficient. A small delay between castings will prevent the druid from having more than two molten boulders in play at any one time.
 * Description: Rolls a burning globe of magma, causing knockback damage
 * Level prerequisite: 6
 * Skill prerequisite: Firestorm
 * Mouse button: Left or right

Arctic Blast
This unusual spell lets the caster determine how long the spell will be cast; as long as mana holds out (and you hold down the casting button), Arctic blast will hold forth. Better yet, the spell can be swept in any direction--just aim while it is activated to freeze enemies on all sides. This spell is best used when you're with a party or summoned creature that can administer damage while the enemy crowds are immobile.
 * Description: Emits a gout of frozen air at enemies in front of the character
 * Level prerequisite: 6
 * Skill prerequisite: None
 * Mouse button: Left or right

Fissure
This spell can be directed at any piece of ground, preferably beneath the scampering feet of a crowd of enemies, who will all suffer fire damage in a region near the casting target.
 * Description: An area attack that causes fire damage by cracking open the earth's crust beneath enemies
 * Level prerequisite: 12
 * Skill prerequisite: Molten Boulder
 * Mouse button: Right

Cyclone Armor
This spell acts like a disposable piece of armor, which absorbs fire, lightning, and cold attacks until it can no longer do so. Its longevity is roughly indicated by the number of swirling blobs of light surrounding the character--as the armor wears off, the number of blobs drops from three to zero.
 * Description: A personal aura that protects against all elemental damages except poison
 * Level prerequisite: 12
 * Skill prerequisite: Arctic Blast
 * Mouse button: Right

Twister
This spell can be targeted at the ground and will affect any enemy that it contacts along the way. Affected enemies are stunned for a duration based on the skill level. This spell can be activated with the left mouse button and requires relatively little mana, so it is suitable as a primary attack.
 * Description: Sends a small group of whirlwinds on an erratic course from the druid to the target spot
 * Level prerequisite: 18
 * Skill prerequisite: Cyclone Armor
 * Mouse button: Left or right

Volcano
A druid can summon a volcano on any open piece of ground. Enemies near the crater receive instant damage, but enemies all around the site are affected by the magma that drops from the sky as well. Cast volcano in enemy groups, and put the target point on or near the toughest foes.
 * Description: Pops a hole in the ground, through which globs of magma erupt and fall to the ground on all sides
 * Level prerequisite: 24
 * Skill prerequisite: Fissure
 * Mouse button: Right

Tornado
While tornadoes do a respectable job of hitting their target, they do not always make contact, due to their erratic motion. It is possible to have multiple tornadoes in motion at one time. This spell can be activated with the left mouse button, and requires relatively little mana, so it is suitable as a primary attack, especially when combined with the solar creeper, which drains mana from corpses.
 * Description: Creates a funnel cloud that moves generally in a straight line from the caster to the target point
 * Level prerequisite: 24
 * Skill prerequisite: Twister
 * Mouse button: Left or right

Armageddon
A devastating area-effect spell, armageddon's rain of fire follows the druid as the druid moves, until its duration runs out. A short delay between castings prevents more than two of these spells to be active at once. Any creature or piece of ground may be targeted to activate the spell, but the fire damage will occur only in the vicinity of the druid.
 * Description: Brings fire damage down from the skies around the casting druid
 * Level prerequisite: 30
 * Skill prerequisite: Volcano, Hurricane
 * Mouse button: Right

Hurricane
A hurricane may be cast at any target or piece of ground but will always activate itself around the druid himself. This spell will follow the druid as he moves, letting him sweep the spell's effects through large crowds as well as simply enjoy the effects of the spell on surrounding monsters while he fights hand to hand.
 * Description: Envelops the druid in a swirling storm that damages all nearby monsters
 * Level prerequisite: 30
 * Skill prerequisite: Tornado
 * Mouse button: Right