This display stuns the world's most powerful figures, including Fleet Admiral Sengoku, the three Admirals (Akainu, Kizaru, and Aokiji), and even Whitebeard himself. Why This Moment Mattered
Furthermore, there are subtle suggestions of (Kenbunshoku). While never explicitly named, Luffy’s ability to instinctively dodge a barrage of lasers from Pacifista—situations that previously required concerted effort—hints at a fraying connection to his latent senses. More tellingly, his desperate use of Armament Haki (Busoshoku) is notable only by its absence. When Luffy strikes Admiral Akainu, his rubber fist burns and melts from the magma’s heat, causing him agonizing pain. A competent user of Armament Haki could have shielded his fist. Luffy cannot. This failure is not a plot hole but a deliberate narrative signal: he is spiritually and physically unprepared for this tier of combat.
In Marineford, Luffy proved he was a King (by unlocking Conqueror's Haki) but showed he was still a child (by lacking the skill to control it).
What was the strength of Luffy's Conqueror Haki in Marineford?
Luffy had zero capability to use Armament Haki at Marineford. If he had, he might have been able to land a hit on Aokiji or Smoker.
While Luffy had previously tapped into this power unconsciously—most notably on Amazon Lily—his use of it at Marineford was a "point of no return".
During the Summit War, Luffy had in Haki. He did not know what "Conqueror’s Haki" (Haoshoku Haki) was, nor did he know how to activate it at will.