What is Skarner?
I really feel that RIOT has had a hard time defining what role this champion plays. I'll put a tldr at the bottom with my personal conclusulion, but the goal of this thread is to attempt to define Skarner's role as a champion, and somewhat establish his identity.
For starters let's begin with a small history. When Skarner was released, he was shown to be an inescapable predator. He came equipped with a permanent slow once he got on top of you. This was later deemed unfair/unfun and removed.
Without the slows, Skarner initially suffered but he was eventually compensated with a new set of passives: crystal venom allowed Skarner to stun someone if he could land 3 spells on them. His movement speed on w gained a ramp up time and it's attack speed component was removed. His q gained a stacking component granting him move and attack speed. He seemed in a good spot at that time.
Then came the juggernauts. Riot began a process of trying to redefine their champion categories to help players (and them) better understand what their champions do and what roles they perform in the game. It was at this point they labeled Skarner as a juggernaut.
It didn't take long before Riot realized that what they envision a juggernaut to be was NOT what Skarner was. Nor did their magic rock kit change aid in pushing Skarner in that direction. To keep things at least slightly brief, the last I heard them saying is that Skarner is probably more of a vanguard.
I believe that RIOT is still off track, and here are my thoughts:
Skarner is not a juggernaut: Riot has already stated this, but to clear it up to others, I'll share my understanding. Juggernauts are high damage, somewhat tanky fighters that are dangerous to fight head on. They generally don't have great c.c., and are usually immobile. Skarner by contrast deals damage over extended fights. He has a slow, a stun, a suppression, and a move speed steroid. Juggernauts can usually be avoided by simply walking away. Not so as Skarner. My iconic juggernaut would be Illaoi.
I don't believe Skarner to be a vanguard. Feel free to correct me if I am wrong, but vanguards are initiating tanks. They usually have some way to gap close, accompanied by some kind of aoe c.c. Champions like Sejuani, Amumu, and Malphite come to mind. Skarner has a ramp up speed buff. Not much of a gap closer since he has to run straight at you. On top of that, all of his crowd control is VERY single target focused.
So, what is Skarner? What does he do? Look at his kit. (Ignoring his passive. That is a separate rant) Q- a spammable dps ability, primarily good for procing sheen, an item that has remained core on him since the beginning. W is a shield with a ramp up move speed bonus. His E (overloaded, a different rant) is a ranged slow that can be proced for a stun. His ultimate is a single target suppression and displacement. With all of the single target lockdown and a pure dps ability, ranged slow and a movespeed buff, i really feel like this guy is a duelist. A skirmisher, similar to a Fiora or a Jax. Jax is a duelist, who's function in a teamfight is a diver. Fiora is a carry. Aside from being good at fighting 1v1 and 1v2, what would Skarner provide to a teamfight? His secondary function is a Warden. His single target lockdown is great for stopping assassin's and divers. Is he the best warden? No, and nor should he be.
Tldr- Skarner is a duelist/skirmisher with a secondary function as a warden in team fights. His kit is made for dueling and punishing bad positioning. He is a hunter, so lose the rocks and get back to hunting down those who threaten your sleeping brethren.
"No escape!!" "Now I've got you!!" "Bwahahahahaha!!!"

