This hero, if played correctly is the most annoying hero in the game. It can disable a whole team at the same time, which is basically a game winner. The problem is disabling the correct heroes and disabling more than 3 heroes is very hard. Thus it makes this a moderately hard hero to play.

Stats

Attack Type=Ranged
Attack Damage=42-48
Attack Range=500

Movementspeed=300
Turnrate=320
Armor=3.96
MagicArmor=5.5

Strength=17
Agility=14
Intelligence=20

Strength per level=2.1
Agility per level=1.0
Intelligence per level=3.4

Spells

Glacial Blasts

The Tempest blasts a target enemy with
icy winds, chilling it every two seconds.
Being chilled causes the target to take
damage and be stunned briefly.
Level 1 : Deals 30 magic damage, stuns for 1 seconds, 1 impact
Level 2 : Deals 40 magic damage, stuns for 1 seconds, 2 impact
Level 3 : Deals 65 magic damage, stuns for 1 seconds, 2 impact
Level 4 : Deals 80 magic damage, stuns for 1 seconds, 3 impact
Mana cost 110/130/150/160
Cooldown 15 seconds

Note: GB is a powerful stunning attack that cannot be underestimated. Even though a 1 second stun doesn't sound like much. You will be amazed at how much damage 5 heroes can fit into 1 second. Further more at level 4 it performs the ability 3 times with one cast ( dealing 80 x 3 and 1 second stun x 3).

Elemental

The Tempest sacrifices a target unit
and extracts from it the very elements
that composed its being. With these
elements, the tempest creates three
Elementals under his control.
Level 1 : Elemental 200 health, 2 armor, deals 16-24 damage
Level 2 : Elemental 225 health, 3 armor, deals 24-32 damage
Level 3 : Elemental 225 health, 4 armor, deals 34-42 damage
Level 4 : Elemental 275 health, 5 armor, deals 43-51 damage
Mana cost 170
Cooldown 35 seconds
Elemental effects
Kills target giving gold and spawns 3 elementals in its place
After each Elemental has attacked 6 times it spawns a duplicate of itself

Note: Elemental is his main farming ability. It is an incredible skill because it can be used on neutrals ( not ancients). Therefore, this skill is what makes it possible to farm a Portal Key within 7-8 minutes of the game, ON NORMAL MODE  AND EASY MODE. To do this, you need to obtain this ability at least to level 1 but it is advisable to max its level ASAP if you want the maximum results, this is because you can use it to push towers early ( getting extra 700 gold) but also the stronger the creeps are the more last hits it will give.

A mixture of both killing neutral creeps and normal creeps is the best combination. So the trick is, push as far as you can from your tower to the enemy tower, then once the elemental cool down is ready, farm high level neutrals by yourself. All you need to do is keep rotating and as soon as elemental reach at least level 3-4 you can attempt to take a tower down ( even without taking a tower, it is possible to get Portal key within 8-10 min).

Meteor

Attuned to all things natural and cosmic,
the Tempest calls down a meteor that ignites
a target area, causing units within to take
damage over time.
Level 1 : Damages targets in radius, 3% maximum health per second for 7 seconds
Level 2 : Damages targets in radius, 4% maximum health per second for 7 seconds
Level 3 : Damages targets in radius, 5% maximum health per second for 7 seconds
Level 4 : Damages targets in radius, 6% maximum health per second for 7 seconds
Mana cost 95/110/125/140
Cooldown 20 seconds

Note: that this skill is useful for when the enemy has high health, therefore it is usually a less priority skill. Take this skill after all other skills are maximised. also a decent farming skill.

Ultimate

Elemental Void

The Tempest uses his power over the
elements to create an extremely low
pressure system at target location,
causing fierce winds to drag all enemy
units toward that target location, dealing
damage over time.
Level 1 : Deals 30 magic damage per second in 500 radius,  Applies Elemental Void to targets in 400 radius, Deals 60 magic damage to targets in 150 radius.
Level 2 :  Deals 50 magic damage per second in 500 radius,  Applies Elemental Void to targets in 400 radius, Deals 100 magic damage to targets in 150 radius.
Level 3 :  Deals 70 magic damage per second in 500 radius,  Applies Elemental Void to targets in 400 radius, Deals 140 magic damage to targets in 150 radius.
Mana Cost 200/300/400
Cooldown 200/190/180
Channeling Time 4 seconds
Elemental Void effects
Silence
Perplexed
Disarmed
Immobilized

Note: this is A GODLY SKILL STUNNING AN AREA FOR 4 SECONDS, EVEN IF THEY HAVE SHRUNKEN HEAD, NOTHING CAN BLOCK THIS SKILL. the trick with this skill is that PORTAL KEY is needed ASAP, to catch enemies unguarded and make it easier to stun more enemy heroes at once. USE this ABILITY only if there ARE ALLIES NEARBY ( the more allies the better), DON'T USE IT WHEN YOU ARE ALONE OR WHEN THERE IS ONLY ONE ENEMY HERO. Also, IF you can't grab all 5 heroes at once with this skill, AT LEAST GRAB THE HEROES THAT CAN CAST STUN OR INTERRUPT you E.g. Glacius, Thunderbringer, Behemoth. IF you dont grab the stunners, your ultimate becomes useless, UNLESS YOU HAVE SHRUNKEN HEAD.

Main Items

Bottle = Good early in the game for additional mana.

Marchers/ Enhanced Marchers / Post Haste = Need one of these, but PORTAL Key should be obtained asap, and shrunken head is next on that list.

Portal Key = Necessary item in order to cast a better ultimate. Good for escaping, starting ganks etc.

Shrunken head = Necessary item for this hero, IF THE ultimate cant be canceled, and you stun all 5 enemy heroes in one go, your team becomes very very powerful.

Restoration Orb= Necessary item, casting the ultimate twice, what more can you want.

Additional Items

Totem of Kuldra = Great support item.

Frost Field Plate = Survivability and more farming capabilities.

Sacrificial Stone = Less death down time, could be a game winner.

Skill Allocation

Level 1 Elemental

Level 2 GB

Level 3 Elemental

Level 4 GB

Level 5 Elemental

Level 6 EV ( ultimate)

Level 7 Elemental

Level 8 GB

Level 9 GB

Level 10 Meteor

Level 11 EV

Level 12 Meteor

Max Meteor and then the ultimate, lastly add yellow stats.