The Seven Deadly Sins is a standard fantasy action shonen series, and has gained a lot of fans since its been on Netflix, where it is currently streaming. The protagonist is a certain Meliodas, a petite Holy Knight of the Liones kingdom. He leads the namesake Seven Deadly Sins squad, but he is hardly a knight in shining armor.
Meliodas has elements of a hero and a villain in him -- literally -- and he might be considered more of an anti-hero than a true hero, given his motives, his methods and his origins. Meliodas saves the day, but he's not a symbol of peace for the people of Liones.
Point for Meliodas: Seeing The Best In Others
Meliodas is a mixed bag, though he does have many good traits that cement his position as the protagonist of the show as a whole. He was born as the eldest son of the demon king and had all kinds of power and prestige within the demon clan, which was feuding with the angel clan. However, Meliodas didn't see much of a future with that life; instead, he met and fell in love with Elizabeth, an angel, and he changed the course of the entire Holy War as a result. He actually switched sides to the angels, fighting alongside the Stigma coalition to take on the demons, including the notorious Ten Commandments. This even prompted Gowther, the wizard, to transform Mael the archangel into Estarossa the demon to maintain balance.
Meliodas loved Elizabeth and swore to protect her with his very life, and he and Elizabeth faced God and the demon king to defend their position. But they lost, and Meliodas was reborn. However, he was cursed to meet Elizabeth and watch her die over and over as she lived out her life as a mortal woman -- nonstop torment that might have broken a lesser man. Meliodas' love for Elizabeth persisted, however, and even in the present day, with the 107th Elizabeth alive and (somewhat) well, Meliodas is as devoted to her as ever.
And that's not all. Meliodas has fought for good and for evil, so he knows that people can change and that false impressions can be deadly. A few years before the main events of the series, Meliodas met Diane, the lonely giant, and befriended her despite her intimidating size and her race's reputation for violence. Diane was delighted and even fell in love with this petite boy who saw her as a person, and not just as a warmongering titan.
Meliodas also met Ban in prison and gave the immortal man a new purpose and a new lease on life, and Meliodas recognized the exile King as a proper leader, and not as a failure to his people. Meliodas will find a lost soul and give them new purpose, and that earned him the intense loyalty of the other Sins, including the brilliant wizard Merlin and the world's mightiest human, the musclebound Escanor.
Point Against Meliodas: Thinking Only of Himself
Meliodas is a personal hero to the other members of the Seven Deadly Sins, but as a whole, he's not quite so heroic. He contrasts sharply against other anime heroes like All Might, the symbol of peace, and Naruto Uzumaki, the ninja who ended the cycle of hatred and war in his world (among others). All Might and Naruto were not driven by their own interests; instead, they risked it all to make the entire world a better place, and they would sooner give their own lives for the people than act on their most selfish desires.
It's true that at first, Naruto wanted to become the Hokage to earn the admiration and respect of his fellow villagers, but he also wanted to become a great leader and guardian, not a lazy king. Naruto was aghast that the shinobi world was on the brink of destroying itself from endless wars, and he took over Nagato and Yahiko's mission to end the meaningless conflicts. All Might, meanwhile, is rightfully called the symbol of peace, since his mere presence and existence is inspiring enough to rally the people and restore hope. And when All Might fights, he's ready to give it all for them, and that is why he inherited the One For All Quirk.
But what about Meliodas? He fights for the Liones kingdom, but ultimately, he is driven by his love for Elizabeth, and he will do anything, and make any enemy, to protect her. That is virtuous in its own way, but then again, Meliodas will even abandon the other Sins or drive them away if they can't help him, and he seems to care little about the people of the kingdom. He will even switch sides back and forth between angel and demon for Elizabeth's sake, and take on dangerous and risky power for his self-oriented goals. He inspires the other Sins, but that's hit and miss, at best.
Meliodas is also less than charismatic, and he seems to take others for granted, even Elizabeth herself. There's his outrageous groping and harassment of the love of his life, which he does with impunity, and he's not afraid to threaten or intimidate the Sins or other allies for petty reasons, even Hawk, the friendly talking pig. Meliodas may be the sin of wrath, but he seems to have far too much fun with the idea.