Why does Gnar have percentage health damage?
He already has some amazing AD scalings and safe poke, can kite really well, has more cc then most tanks and then completely ruin your day in his mega form, does he really need percentage health damage in the form of magic damage ? And to add icing to the already overpowered cake, he's resourceless.
He would be way more bearable if he couldn't just destroy you regardless of if you tried to counter build him.
Thinking of building armor? Lol screw you.
Thinking of building health? Nope
Thinking of just going straight damage? Good luck, most Gnar's have realized you can go full tank on him and still outdamage most top laners with your poke and base damages.
After he's done zoning you from farm with his resourceless poke and putting you on the defensive, he transforms into his Mega Form and continues to zone you even more with tank stats and his ultimate.
Gnar, unsurprisingly because Riot's balance team has special needs, can also do a tank's job far better then what was intended for him which was to be a tanky AD brusier .
** There's no reason to pick a competent Nautilus/Shen/Sejuani over a competent Gnar, they both have the same functions except Gnar does it better in everyway. Nevermind his amazing base damages and scalings, but the fact that he gets so many free stats and can deal monstrous damage in his "tank" form with just a trinity force. We have a champion that was intended to be a top lane bruiser that can build all tank with just maybe ONE damage item (Normally Trinity Force, which gives good tank stats) and still outclass multiple tanks in every way with his superior cc, amazing damage, amazing mobility, epic engage, mixed damage, versatile kit.**
and 
for the attack speed slows. Against Darius, you can stack armor and health, and while less effective because of his passive Armor pen, it still lessens his damage.
and 
, are impossible to build defenses against. Never mind their kits in general, which many consider to be overloaded, but just in regards to their damage. They are both ranged AD building AA reliant champs. They have AD scaling skills which deal considerable damage, and their AA's do a lot of physical damage too. So you should build armor and health to counter their damage right? Wrong. Because someone thought that it would be great to give them %max health magic damage procs in their kit. And not low proc damage either. Its freaking 20%. So now, to build defenses against these champs, you have to build Armor, MR and Health, and have enough of all of them to get to effective health levels because they are going to be building damage early (or all game in the case of kalista)
. Or have a weak early game like 
. Many have problems escaping ganks, and are kited to death 
. WHY DOES GNAR NEED TO ALWAYS BE GOOD AT EVERY STAGE OF THE GAME? Its as if people think Gnar would be worthless if he weren't a lane bully. Is being a mobile, tanky, safe laner/pick, resourceless, and CC monster not good enough for you? Gnar has to be a lane bully to?
. However, there aren't enough champs in the top lane than can do this.
beats X champion top, is no different than saying 
is better than another jungler so he must be balanced. Second Riven DOES NOT beat a competent Gnar. Third 
and 
and he still would kite you silly.
to his beta state, because that's "what he was meant to be". Lets buff 
You're on your own pal!
First it's sweet, then it's sour!
a gapcloser. Right now, teemo is balanced by the fact that gapclosing champions can beat him, and gnar is literally teemo v2 in lane. Now with un-itemisable stats and good teamfight utility.
. Even when she did get nerfed she still has a hell of a lot of poke
