Hello Folks,

Offense Build is best for the build im about to describe at level 30, however leveling I suggest going into the utility tree for extra support in obtaining items and being able to keep from dying.
Offense Tree-
4 Sorcery 4 Fury
4 Deadliness
1 Weapon Expertise 3 Havoc
2 Lethality 2 Brute Force
1 Frenzy 1 Sunder
1 Executioner

Support Tree-
3 Meditation 1 Summoner's Insight
1 Mastermind (To help you move back to lane quicker)

Alright now I know many people will just tell you what to build and how you can have different variables in items and maybe in what order I have a more specific way of building.

Starting Items-
Boots - Health Potion x2 - Mana Potion x2
2nd Store Visit
Sapphire Crystal - Sapphire Crystal - Health Potion x2 - Mana Potion x2 (Best to get in one go approx. 840 gold.)
3rd Store Visit
Amplifying Tome - Sheen - Health Potion x2 - Mana Potion x2 -Approx 940 Gold.
4th Store Visit
Chain Vest - Glacial Shroud - Iceborn Gauntlet

Mid. Game Items
Berserker's Greaves - Recurve Bow - B. F. Sword - Vampiric Scepter - Bloodthirster- Pickaxe - Vampiric Scepter - Tiamat - Ravenous Hydra

End Game!
Sell Recurve Bow - Zeal - Cloak of Agility - Phantom Dancer - 2nd Bloodthirster or Blade of the Ruined King which ever you deem acceptable. I prefer Blade of the Ruined King for the quick 15% on Tanks if I chose to engage one.

Summoner Spells - Teleport, Flash.
I level all of my abilities together Starting with Ixtal's Impact, then Shattered Earth and finally with Seismic Bastion Repeating that until level 6 then skip Seismic Bastion for Impale ( Making your skill levels Shattered Earth-2 Seismic Bastion-1 Ixtal's Impact-2 Impale-1 ) Repeat that until lvl 18.

Early Game - Levels 1-6 (Champ initiations)

When I open or initiate attacks on an enemy champion with nearby enemy units around I usually choose to run through the mobs (Smartest to have them attacking your laning units) and use Shattered Earth to charge it for guaranteed slow, you may use Seismic Bastion to move in quicker, or save it if the enemy champ does not put out enough damage and use it as a get away spell.
Ixtal's Impact is #1 skill because it is ABSOLUTELY the core of your laning phase it adds the high damage output for level one you want, bonus damage on consumed marks, and an added bonus heal. Use it to your advantage, You may also use Shattered Earth to consume all possible marks in the given radius of the attack, I use the range on it to heal without being harassed by enemy champs or even to snag extra gold here and there.

If by level 6 you have not already acquired a kill this is the time to do so, the first 8-12 minutes of your play are the seemingly most important minutes of the game it determines whether you will become support to other lanes after pushing yours or roam around and just pick people off 1 by 1.

Because of the item set up I have displayed for you, you will realize the mana issues most skarner guides have will be obsolete allowing you to do more damage at a early level, At level 6 to get a fast kill poke the enemy with Ixtal's Impact till Half to three quarter hp depending on the movement abilities of the opposition then charge Shattered Earth Slow and apply damage till almost in tower range and then pull ( Impale) them back and continue, finish them with a Ixtal's Impact if need be. For instance, If I am mid lane against a Annie I will go in at 3/4th hp without a worry of not obtaining a kill, using the method previously stated. However with a Fizz or a champ with abilities meant to help them avoid damage upon use I start with a early impale to burst them down quickly and a flash to keep up with the move away.

Mid to End game is pretty much the same, if one enemy gets too powerful coordinate with your team using your Impale to shut him down. AVOID 1v3! 1v2 is do-able at one point depending on you skill at avoiding attacks and choosing who to attack, 3v1 is not however.

Pros: Very powerful and if you play aggressive but smart and use Ixtal's Impact to heal yourself quickly it has a high sustain along with the Lifesteal you will have. Low Cool Down Time. Fully Built can Solo Baron . Good at damaging towers quickly after Sheen is built. I side farm Jungle buffs while moving between lanes. Blue is recommended whenever possible! The more mana the more Carnage! Short CD For the Win!

Cons: Don't move much higher than 2400 Hp even at end game, Lifesteal makes up for it. Only Champs able to kill you at this point if fully built is Attack Speed Crit champions like Yi. Which is evenly matched if you open up the attack with an impale or use it when he has his ultimate up. Use it smart!
Usually first targeted in Team fights because of damage output. Wait until spells are used by enemy team to engage for maximum damage without being killed fast.

Things to think about while running. Skarner is a close ranged combat, Earlier today I was being chased by a Half-Dead Teemo near baron while returning with 25% to mid to clear creatures and recall. I realized if I turned around he could apply a slow and turn and kite me til death, futile attempt right? So I ran into baron to limit visibility and range between us turned around and killed him returning to the task at hand. Use Terrain to your advantage!

While going mid as Skarner you will learn if a good ranged player goes mid that knows how to harass your health you will not be able to do much. Now at level three you will find this to be the tide turner.
A fear tactic I do that makes people panic is act scared of the other player until level 3 avoiding damage and just helping creatures from afar and trying to tag them with Ixtal's Impact Healing myself with 1 hit on a marked unit to heal myself. Only dive for one mark because the healing amount is halved each time. At level three use Shattered Earth once to charge it and Flash into the enemy throwing down all your spells as quickly as possible maintaining basic attacks. DO NOT TOWER DIVE!!! You will 3/5 times die! Let them run because if they are stupid and come back it is easy to accomplish a kill. If they recall that's more Exp and Gold for you while they are absent. At lvl 6 it gives you the ability to switch between lanes and position yourself for a jump, Use the lane that is being pushed the most and use your ulti to drag enemies into other team-mates or towers.
AND AS ALWAYS PAY ATTENTION TO ENEMY MOVEMENT DONT GET CAUGHT OFFGAURD HE HAS AMAZING ESCAPABILITY.