In One Piece, Portgas D. Ace is the first person to consume the Mera Mera no Mi devil fruit, which grants him immense power and the ability to control fire. His fiery abilities are highly compatible with his personality.
Ace is regarded as a strong character, much like his younger brother Luffy. Many times, he makes decisions impulsively and based on instinct, without considering the potential consequences before acting. Ultimately, he makes several serious mistakes that should not have happened, leading to significant issues and even forcing him to confront the very nature of his existence.
Let’s take a look at three serious mistakes that Portgas D. Ace made in One Piece!
1. Underestimating the threat of Blackbeard’s crew

An excerpt from Chapter 552 reveals that Ace had previously underestimated Blackbeard during a confrontation with him, following the murder of Thatch. Blackbeard had a bad feeling about this encounter. However, in the end, Ace decided to continue pursuing Blackbeard.
This is a serious mistake because Ace only worsened the situation. The downfall of his brother Luffy was devastating. He failed to anticipate the consequences of confronting Blackbeard.
2. Chasing Blackbeard without understanding his power
Portgas D. Ace went after Blackbeard without fully understanding the extent of his powers. This lapse in judgment turned into a major issue, as after that, Blackbeard revealed himself to be much stronger than Ace. As a result, Ace was completely defeated in their encounter.
In Chapter 441, Ace was shocked to discover that his own devil fruit powers did not “function” as expected when confronted with the Yami Yami no Mi powers of Blackbeard. It became evident that Blackbeard could defeat Ace without much difficulty.
Though both Ace and Teach were once part of the Blackbeard crew, Ace failed to recognize Teach as the cunning and treacherous individual he truly was. This ignorance led to Ace’s defeat at the hands of Blackbeard, leaving him feeling regretful about his own decisions.
Moreover, Ace’s defeat by Marshall D. Teach/Blackbeard created a monumental impact on the storyline of One Piece. Blackbeard delivered Ace to the Marines, which led to a war at Marineford, resulting in the deaths of both Blackbeard and Ace.
Teach himself manipulated the situation to gain victory over Ace, subsequently rising to power as one of the Four Emperors, while also capturing many renowned individuals at Impel Down. Ultimately, the fatal blow delivered to Ace came from Blackbeard wielding the Gura Gura no Mi powers.
3. Succumbing to provocation by Admiral Akainu

At that moment, Izo tried to warn Ace not to be provoked, but Ace charged directly at Akainu. Following their encounter, Ace felt that Akainu’s magma powers were much stronger than his own fire abilities.
In a twist, Akainu then directed his fury towards Luffy. The tragic event unfolded as we know it, with Ace sacrificing himself to protect his beloved brother Luffy. The moment Ace stepped in front of Akainu’s fatal blow for Luffy left a lasting emotional impact that no one could forget.