Skarner is becoming overloaded.
Not overpowered, overloaded. There's a difference. For those who don't know, overloaded means that the champions kit has so many different effects and abilities stuffed into it, that it can seem confusing and overwhelming.
He's not the only one, Kalista and Lee Sin are also pretty overloaded. Mordekaiser seems like he's on the way to it, too.
Overloaded champions always have one of two different fates. Either they're overpowered, or underpowered. Historically, overloaded champions like Lee Sin and Kalista have been overpowered, but, iirc, Kalista leans towards underpowered. There's a reason for this. With so much stuff added into a kit, either everything they do is mediocre, or they're really good at one thing and then have loads of other utility to add onto it. For example, Lee Sin used to have bonus Life Steal, Spell Vamp, and an Attack Speed reduction. This is on top of his mobility, damage, resource sustain, and Attack Speed bonuses. Before some of that was removed, he was really good at dealing early damage, and then all of the other things overloaded onto him just helped that early damage spike, and Lee Sin became extremely dominant.
Skarner is beginning to suffer the same fate, except he's on the underpowered side (And, since I've always loved Skarner, that worries me). Recall that this is Skarners third(?) kit rework. Every new kit since has had his old passive, or at least a version of it, baked into his new kit. When he was reworked at first, they took his old passive and tied it to his Q. During this rework, they're taking his passive and tying it to his E. And it shows - If you mouse over Skarner right now on champion select, you'll see his Q has a HUGE entry, lots of text, while his other abilities are one sentence.
I think they need to more properly rework him. And the first step is determining his fantasy. Right now, there are SO MANY different fantasies going around for Skarner, both at Riot and in the playerbase. Some people see him as an unstoppable predator (How he was described in his original rework), who, no matter where you go, can always run you down and drag you back to hell, similar to Hecarim and Udyr. Some people see him as a guardian, like in his lore (Old and new), protecting his allies with his tankiness and CC. And still others see him as a kidnapper, which is best exemplified in his Battlecast skin. "Specialization: Target Apprehension". And still others might see him as a manipulator of crystal magic, now that his presence can apparently raise crystal towers from the ground.
One of these fantasies needs to be picked as the core fantasy, and a new kit designed around that fantasy should come to light. Currently... He just looks like a bunch of abilities, stats, and effects stuffed into a champion, in an attempt to make that champion viable/better.