I played a few Skarner games recently and a few things stuck out at me. First, his early game is just plain bad. He isn't very tanky and he doesn't do enough damage to stay alive against an aggressive jungler. Once I was able to complete my first two items, namely
and
, my damage output spiked and I was able to make good plays for my team. Once the game got to mid/late game, I was tanky enough and did enough damage to be a real threat. I became an absolute monster.
Second, his spires are honestly a gimmick. His dueling potential early in the spire isn't really any better than outside of the spire. Sure, you get greater attack speed, but when they nerfed the spire attack speed many patches ago, they made them so weak early game that it doesn't matter if you are fighting in one. With how situational and poor the opportunities to hunt someone in a spire are, those things should damn near make Skarner unkillable while hes in them. They either need to provide him with greater attack damage, empower his abilities, or make him tankier.
If your team doesn't have much early game pressure or loses lanes early on, then you probably won't make enough of an impact to survive to late game. If you can hold out until late game, Skarner brings enough power to singlehandedly win trades. I can understand why Riot classified him as a juggernaut.