Well probably he's one of the most underrated chara in the series. Being compared to smoker, or unable to beat a damn injured admiral or even literally treating weak because of lacking df ability. All of that were obviously retarded. So lemme say this. GARP WAS THE STRONGEST EXISTENCE NEXT TO POSEIDON IN OPVERSE. Maybe there are lots who will disagree about what i said but im going to give some reason why he was the strongest. -first was, garp manage to almost kill roger and manage to survive from the latter with the same intent upon him. And yeah it happened multiple times. Plus the fact that on those times roger were prime and healthy. Well wb manage to par roger but it happened when roger was already sick. -Garp manage to corner roger. This feat was actually underrated. "Cornering" itself implies that roger is running and avoiding a fight from garp. And by knowing roger who was never turning his back against a fight. Well thats makes garp as the only guy who doesnt want roger to be on a clash as much as possible. -to top the cornering thing. Garp was facing the whole roger pirates with unplanned, random, and no name crew. He was just going to hop in at a random ship and face straight roger. Imo that was reckless as dope. -Garp had a name before roger. We can presume that garp is the key in ending the rock's era. The era of goons which compared to unimaginable catastrophy that even 2 yonko making an alliance was incomparable. Yeah he probably saves the whole world from the guys which power was way exceed the power of the yonkos. Thus the title "Hero" is lit. -he pancaked mountains for warming up and nailed down flat chinjao's prime head who said that can split ice continent by half. And he did that with just one normal hakified punch -he also put a stop on a phoenix and revert it back to its human form with the same punch. A feat that the current admirals cant do throughout the war. -His physical raw strength was incomparable and probably the strongest in the series. Able to throw cannonballs that way stronger than the cannons and even throwing a giant iron ball with the size greater than the going merry in a respectable distance. Garp can do all that while having an injury and despite being old. -with destructive punches and being a instructor of young marines. Garp probably had a haki mastery. Lets presume his haki level was on the same as reyleigh (coo,coa). -also as a instructor,it is safe to say he knew rokushiki. And a master of it as well. Now Imagine combining rokushiki with beastly haki and godly raw strength. I doubt akainu will manage to survive from that. Well i guess no one will able to survive. Unless roger was the name. -Garp also has speed. Well with the help of rokushiki. I guess he was on par on luffy's maximum speed. Wb doesnt have that. -he also had respectable endurance and durability. He managed to tank 2nd gear point blank without haki and enhancement from rokushiki. And the thing was he just knock that attack off like a dust. And even the big slash he gwts while sleeping. Well Actually he didnt felt that. -His stamina was also on a different level. Crushing mountains with his raw fist as a warm up was overkill to anyone. No one will do it...coz they cant.... -his battle experience is also the greatest of all. Fighting the rocks, roger, and countless pirates thus getting his ephitet the devil. His experience was at the top. -hes the strongest warrior of the strongest force in the sea, the marines. In fact just by showing himself in the war will boost the morale of all the marines. Much more like they saw a god. -unlike roger and wb, garp manage to stay healthy all this time. We know how health makes a big blow to roger and wb.yeah being healthy was a big factor in overall strength. Garp manage to keep his strength at bay on a long run with age as the only antagonizing factor. That feat makes roger and wb fail.