Skarner is a hybrid figher. Many people dont see the good thing in Skarner. In this guide i'll show you how to own with him.

Runes..
First i must say that Skarner is a late game champion, he gets stronger after rageblade, hextech and giants belt so..
I take flat ap per lvl marks and glyphs what makes you stronger at late game, flat armor runes and ap quints for start. Hextech gives you powerful healing with E and normal attacks. Massive and very often heal from Q can save your live too. Now one of most important items, Rylai's Crystal Scepter. Makes your opponents impossible to run and gives you health

Starting with dorans ring gives you mana regen and ability power. Boots of swiftness let you chase your enemies and slow them with Q after second use, so they cant escape. Rageblade makes well with your W and you can easy take down turrets coz of big attack speed and damage. Lich bane gives you additional massive dmg and a bit magic resist, and last: Rabbadon's deathcap can be also replaced with The Bloodthrister if your team needs more AD.

If you are in 1v1 you should attack your enemy for lower cooldowns, spam your Q, activate the shield for faster attack speed and more health and use your E to heal yourself.

And about ulti:
Try to time your ultis ending and when its about 0.5s to end turn to the opposite direction what makes you be in fron of your enemy and its always some more meters passed than just walking back.

In teamfights you should focus the strongest enemy and pull him to your team with your ulti, so teamfight will be easier. When you have sb on ulti dont forget to spam your Q so you will slow him and lower his hp.

I hope you will find smth usefull in that and sorry for my english if i wrote smth wrong :)