
Vanguard · physical (AD) damage
Skarner is a Vanguard that deals physical (AD) damage and brings suppression, stun, slow. Some of their lockdown (suppression) ignores tenacity, so you dodge it; you can't cleanse or Merc' through it. Below is Skarner's highest-win-rate build from high-elo games; open the counter-build tool to tune it against your specific enemy team.

Skarner's Attacks, Shattered Earth, Upheaval, and Impale, apply Quaking. At max stacks of Quaking, enemies take max Health magic damage over its duration.

Skarner rips a boulder from the earth that empowers his attacks and can be thrown as a powerful projectile.

Skarner gains a shield and creates an earthquake whose shockwave damages and slows foes.

Skarner charges forward and passes through terrain. If he collides with a champion or large monster, he'll slam them into the next wall he hits to damage and stun them.

Skarner's tails lash forward to suppress enemy champions. Once suppressed, the victims will be dragged along by Skarner as he moves around.
R ImpaleStuntenacity helpsFROM
E Ixtal's ImpactSlowignores tenacityFROM
Q Shattered Earth / Upheaval
W Seismic BastionHover a crowd-control type to see which ability it comes from.
Resolve
Grasp of the Undying
Aftershock
Guardian
Demolish
Font of Life
Shield Bash
Conditioning
Second Wind
Bone Plating
Overgrowth
Revitalize
Unflinching
Inspiration
Glacial Augment
Unsealed Spellbook
First Strike
Hextech Flashtraption
Magical Footwear
Cash Back
Triple Tonic
Time Warp Tonic
Biscuit Delivery
Cosmic Insight
Approach Velocity
Jack Of All Trades

Based on 2335 games · 54.8% win rate · challenger+grandmaster+master+emerald-diamond+platinum-emerald · patch 16.18.1.
Domination
Electrocute
Dark Harvest
Hail of Blades
Cheap Shot
Taste of Blood
Sudden Impact
Sixth Sense
Grisly Mementos
Deep Ward
Treasure Hunter
Relentless Hunter
Ultimate Hunter
Inspiration
Glacial Augment
Unsealed Spellbook
First Strike
Hextech Flashtraption
Magical Footwear
Cash Back
Triple Tonic
Time Warp Tonic
Biscuit Delivery
Cosmic Insight
Approach Velocity
Jack Of All Trades

Based on 271 games · 44.3% win rate · challenger+grandmaster+master+emerald-diamond+platinum-emerald · patch 16.18.1.
Resolve
Grasp of the Undying
Aftershock
Guardian
Demolish
Font of Life
Shield Bash
Conditioning
Second Wind
Bone Plating
Overgrowth
Revitalize
Unflinching
Sorcery
Summon Aery
Arcane Comet
Deathfire Touch
Axiom Arcanist
Manaflow Band
Nimbus Cloak
Transcendence
Celerity
Absolute Focus
Scorch
Waterwalking
Gathering Storm

Based on 239 games · 51% win rate · challenger+grandmaster+master+emerald-diamond+platinum-emerald · patch 16.18.1.