AP/Hybrid Skarner top [GOT NERFED RIP]

I start dring most of the time, but you can potentially go sapphire crystal to get sheen earlier, Dshield is for when you go against something thats going to be poking you constantly with basic attacks

Always start with sheen, its one of your biggest powerspikes, after it you can really build any of the next 3 items in whatever order you need, though I prefer to go gunblade for the active on those slippery targets and the spell vamp for survivability. Nashor's is there for the atk speed and cdr mostly, a lot of your damage is going to come from your Q empowered autos since those scale with AP. Lich and Rabadon are obvious, Spirit Visage if they have any ap characters is good because it will be multiplying your shield, your E heal and your spell vamp/lifesteal/regen

Don't be afraid to build one or two defensive items, specially if your team needs a tankier skarner with them, most of these are self explanatory, my main 2 are always spirit visage and frozen heart just because they are incredible items that also give you that 20% CDR you are always lacking after nashor's. Randuin's is useful when they got slippery enemies that will get punished for kiting you instead of just running away, remember this randuin's doesn't give crit dmg reduction but instead has a slow on move and attack speed on being hit. FON just has insane MR alongside movement speed which is always appreciated by good ol' skarner

ROA: I have been trying this one out recently, it definitely makes you way more tanky and I have felt it made me survive many encounters I wouldn't have with gunblade alone, but it does slow your build down, definitely build it if you see this game going to late, but always after Sheen

Spirit of the spectral wraith: CDR and more spellvamp packed into one item, could be useful, haven't had many chances to try it out, you could definitely build it if you take this jungle

Void staff: self explanatory, build if they have a lot of MR

Abyssal scepter: You will always be melee range so the aura is always useful, definitely consider it if both your team and the enemy has magic damage, its free flat pen on you

Malady: Good because it gives you AS, penetration on basic attacks and more dmg on hit, it's better if you find that you are involved in more extended fights

Morello: I dont really like building this item, but it's your best antiheal source against champions like nasus or ap yi, necessary if you end up not going ignite and your team isn't building it either. Though the 40% health requirement is a brutal one, which is why you might want to build Executioner's Calling, but its really a last resort type of item.

Liandry's: I don't love the item in this version of League, but since Skarner applies a permaslow while fighting you always get the bonus dmg without building Rylai's, though I only build it vs HP stacking champions like those that build Atmogs or a Cho'Gath/Sion

Swifties for teams with a lot of slows where the duration doesnt really matter since they just get reapplied, it also gives you the highest move speed besides Mobis, Tabis for auto attack heavy comps and merc treads for shit like fiddlesticks or other CC heavy characters. Mobi boots in case you just want to move fast around the map or gank lanes/opponents before they have a chance to react to you. If you go Lucidity boots I do recommend getting 2 points on CDR for 4% from masteries and then 1 rune on CDR to get 40% after either Nashor's/Spirit Visage/Frozen Heart, try not to surpass the 40% limit or you will just be losing gold.