Gnar is an unfair champion

He just has it all.

1. No mana costs (so he can keep using abilities at no cost)
2. He can kite and poke you into oblivion
3. Insane mobility with his jumps (allows him to escape or close the gap and burst too if he wants)
4. Insane Tankiness even without items
5. AD champ so you can't leave him, he'll push your towers down
6. Insane CC means he's very useful in team fights later so you can't outscale him either

People say... "Just dodge his boomerang and out-trade him." The problem is that in Top most of his match-ups are melee. And melee champs can't trade back against ranged very well unless the minion wave is just right. Otherwise you end up taking more damage even though you landed multiple abilities on him because on your way back to your side of the lane you'll get hit by minion aggro on top of his auto-attacks. Also, his boomerangs are mana-less which means he can just try again and again and again.

He's fundamentally broken and unfun to play against. And because he has long range AND can close the gap with his ability; if he gets so much as 1 kill he can keep abusing you with very little chance of you coming back.

Match-ups like this are why I stay away from Top...