"You didn't beat me. You ignored the rules of engagement. In a fair fight, I'd kill you."
"That's not much incentive for me to fight fair, then, is it?"
― Will Turner and Jack Sparrow (Pirates of the Caribbean: The Curse of the Black Pearl)
"I had thought that the man who killed Ou Ki would have been of a far greater caliber."
"Quite the opposite. It is precisely I am such a small man that I was able to win. It is because I am a coward that I dedicate so much myself to petty little schemes. I will gladly resort to anything , even underhanded methods if it means we can emerge unharmed. The level of detail in my plans correlates directly to how much of a coward I am."
― Ryo Fui and Ri Boku (Kingdom Vol.17)
"You are free to call us cowards once you are dead!!!The one who survived is the victor!!!"
― Dagama (One Piece)
"Only a moron would bring a sword to a gun fight."
― Skulduggery Pleasant (Skulduggery Pleasant)
The ability to embody the combat pragmatist archetype. Note this is essentially a definition of an archetype/concept.
The character is an advantage-seeker. They are defined by their willingness to win by any means necessary. Such characters will often cheat or bend the rules of any norm, in order to gain the upper hand over the opposition. Strategically, they are very much unpredictable and can be considered dishonorable compared to more moralistic fighters. However, they are definitely not cowardly, being more opportunistic and inventive when the odds are stacked against them. Essentially, these characters are much more realistic when it comes to non-fictional representations of battle and war.
Eren Yaeger (Attack on Titan) has resolved himself to do what ever is necessary to save his people, including manipulating his half-brother, betraying his friends, and destroying the entire world.
Sosuke Aizen (Bleach) can come up with any pragmatic advantages and plans for his goals to overthrow the Soul King.
Kisuke Urahara (Bleach) is well known for his ability to prepare for any possible situation.
Lelouch vi Britannia (Code Geass) uses every advantage available to him to take down his enemies.
In the past, Vegeta (Dragon Ball series) would take any advantages available to him, including killing civilians or even allowing himself to be fatally wounded in order get a Zenkai boost.
Lacking innate talent, Issei Hyodou (Highschool DxD) relied on pragmatism, using abnormal ways that is considered foolish to fight even managed to best combat geniuses like Vali and Cao Cao.
Since his youth, Joseph Joestar (JoJo's Bizarre Adventure) has mixed his intelligence and wit with a variety of equipment to catch his opponents off guard.
Ri Boku (Kingdom)
Kan Ki (Kingdom)
Ka Rin (Kingdom)
Arsène Lupin III (Lupin III) is a slippery Thief with many tricks.
With his Quirk, All For One (My Hero Academia) can steal the quirks of others, just to counter his opponents. This has made him both highly dangerous and nigh-unstoppable.
Renowned for his deceptive tactics, Itachi Uchiha (Naruto) was able to face down powerful shinobi like Orochimaru, Deidara, and Kakashi Hatake on equal ground with superb and incredible mastery over potent genjutsu.
Known as the Copy Ninja, Kakashi Hatake (Right) (Naruto) could learn the jutsu of his opponents with his Sharingan, being able to quickly mimic them.
Overtime, Sasuke Uchiha (Left) and Naruto Uzumaki (Right) (Naruto) gained soo many skills and jutsu, neither one could best the other.
As a shinobi and warrior from over 100 years ago, Madara Uchiha (Naruto) was legendary for his quick, adaptive combat style.
"Foul-Play" Krieg (One Piece) lives up to his moniker for his pragmatic ideals by using any means necessary to achieve victory.
Crocodile (One Piece) strives to achieve victory at all cost, whether it be sacrificing even his subordinates or eschewing honor in combat.
Donquixote Doflamingo (One Piece) uses any means to gain the advantage, whether to falsify his resignation from the Warlords or destroying the entire Dressrosa to kill all his enemies.
Sakazuki (One Piece) is willing to use any means to win, such as deceiving Squard or taunting Ace about Whitebeard in order to gain the advantages.
Hody Jones (One Piece) and his New Fish-Men Pirates crew are pragmatists in that they would use any methods to overwhelm mankind, including drug abuse and destroying the entire Fish-Man Island.
Merlin (Seven Deadly Sins) mixes her power of Infinity with her mastery of magic to a point that others consider her strength unfair.
Rimuru Tempest (That Time I got Reincarnated as a Slime) cleverly used his wide range of abilities to his advantage.