Just like the title says and why is that champ his counter

When I play against Graves, I like to take Miss Fortune or Draven. Both outrange him by 25, have the ability to outburst him, AND outtrade him. They don't have the same AOE power he does, especially in teamfights, but they can do well in lane. MF can poke and burst with Double Up and autoattacks, and then follow up with Impure Shots' active to win the autoattack trading after. Draven can poke with Spinning Axe, then burst/trade with Stand Aside and Blood Rush.

The bulk of Graves' damage lies in his Buckshot, especially at close range. If Graves goes in on you, try to avoid his Buckshot, but stand your ground after he uses it and keep autoattacking him. MF and Draven excel in the longer trades once Buckshot is out of the way.

You can fight fire with fire ^^ and pick a harass heavy champ like Tiza said, or you can pick someone like Trist who is far superior late game and just out-farm him, and her range and burst potential allow her to safely farm, harass, and burst when necessary. Only downfall is trist is strong lvls 1 and 2, and `~15-18, her mid game is mediocre at best unless shes supa fed.

I find that Sivir is also pretty good against Graves, but only if you can block Buckshot with Spell Shield. If you can do that and land Boomerang Blade, than you will do well against Graves.

I really like cait, and feel like she's his opposite. If he dashes towards you? Net him and dash away, he firing his q? Fire right back!

The big thing about cait is that you want to deal damage then disengage enough that you can nuke em with your ult.

Cait is really effective against him, since she has farther reach and can poke with him without trade. When he dash, you can net to escape. And you can control/zone him with traps.

Trist can also do this after some levels, and she has good AS steriods and a great escape.

MF has better trading potential than Graves, but a good Smokescreen can ruin it all for her.

I find Tristana to be a relatively safe pick against Graves.

You can also get the only other "tank AD" : Urgot. He will sort of nullify Graves' passive with his E and have way more resistance in the end.

Corki/Sivir are skill picks.

Vayne can beat him in the long run.

I wouldn't pick others.

Graves is very good in the early game due to his high burst damage and toughness. He will usually have an aggressive support like Blitzcrank or Alistar/Taric.

To beat him, poking at him is generally the best way to go. Its hard to outfight him, so instead you out-dink him. Even with his bad AA range, his Shotgun is fast and accurate and longrange so this is challenging.

Therefore you need a good constant poke and a healing champ. However you need to be able to DISENGAGE as well. If taric stuns or Blitz pulls, you can be taken out by a quick barrage of Graves skills.
Hence, Ezreal works quite well due to his poke and great range, and ability to GTFO if grabbed/stunned.
Corki is alright but has weaker range than Graves with his grenade.
Trist is ok but her range sucks too early on. She has high burst at 6 but less survvial.
Caitlyn is great at poking away at him, but she doesnt have the burst potential and her endgame isn't quite as good as certain others.

I like using Corki vs Graves. He can poke from farther away. He can burst just as hard as graves, can blink farther than graves can during lane, and deals more sustained damage with gatling gun and hextech shrapnel.