.... He has plenty of hard counters. Targon completely counters him, as the Fear forces skrime to walk away, wasting a lot of his cc combo potential. Targon's durability makes him impossible for skrime to kill straight up. Targon has a lot more base health regeneration than Skrime. Skrimes health regen is actually one of the lowest amongst all tanks, so taht if he's not standing on his turret, he wont' be getting his health back very quickly. This is something major to keep in mind, since it means that when he doesnt' have his shield up, he's vunerable to being poked out.
Targon doesn't have the same weakness to the same type of poke as skrime due to his higher health regen and better sustain tools.
Nefara also does very well vs Skrime. Her W knock back forces him away long enough for her to use the Q which will silence and interrupt his abilities, and the root which keeps him out of melee. With proper E placement, she can both get out of his roots and melee range, or throw him away once again, creating a gap. Without his ult, Skrime lacks anything in his kit to keep him in melee range and auto attacking. His Attack range also reflects this.
Skrime has numerous weaknesses in lane which can easily be exploited. Where he shines is that of all the tank/brawlers, he has the highest kill potentital due to the early game threat his Q E provides. However, he also suffers weakness in that if his Q is dodged, and his opponent has any form of sustain, his E poke will not be enough.
As such, if I had to list commanders who excell at or counter Skrime
Itarri/Mackwell - Both have escapes that also come equipped with strong slows/roots which will keep him away.
Targon - His durability and sustain makes him a natural at simply out sustaining skrime. As well, his overall lower mana costs means that he will be able to keep fighting much longer since a skrime with no mana, has no real ways to shine.
Nefara - With a kite thats loaded with more ways to kite than a professional kite flying competition, its a natural that she would excel at disenaging and disrupting him . Her ult also renders his AA, which is the biggest source of his dmg in extended trades pointless giving her another edge.
Slith - Believe it or not, the snake is a nightmare for Skrime. Skrime has only one way to approach an enemy, Walk up, or his Q line. Slith will almost always hide behind a minion wave, throwing his Q's to smash skrime whenver his shield isn't up. If skrime tries to walk up and start trading, his line stun is nearly impossible for skrime to avoid if he wants to take an offensive stance. As such, skrime is forced into a poke war against a commander who out ranges his E with every ability.
Who skrime Counters
Vikka - while her poke is absolutely devasating, she has no hard dashes or CC to disengage. While she could out run him with volt bomb and overclock, she burns more mana than he does in such a trade, and his E can also be used to lock her down while she has her overclock on.
Eos - Despite having a Massive range advantage on skrime, Eos suffers from a lack of escape tools to get away from skrime. While his W providing immunity to slows and damage reduction is solid, skrime relies on Hard CC's rather than slows, making his best escape minimal in usefullness. Eos can still win by out ranging skrime, but doing so, results in him being unable to push lanes, letting skrime take the first turret against him.
J.P. - This caster has no escapes. His minefield is better for zoning than for peeling, and his overheat is likely to screw him. Skrime counters him so hard, although JP can do some damage with his lasers if he plays right. Skrime wins this very hard.
Shaddrach - He doesn't have good durability early game, when Skrime is at his strongest. He also doesn't get a good tool for disengaging skrime until he has his ultimate. This is a very rough lane for Shaddrach
Stormherald - While durable, his Forcefield is usefull at limiting skrimes Auto Attacks, but due to his very poor range, skrime will simply out poke. Stormherald doesn't 'have very strong poke either, which gives skrime's limited sustain a chance to out last stormherald. Stormheralds Q and E are incredible expensive, so Skrime's mana will out last Stormheralds. Skrimes E also can prevent stormherald from using his second E activation to dash away, allowing skrime to secure the kill.