Dabi is a rude and argumentative person who has no sense of respect. He introduced himself to Tomura informally, and refused to give out his real name. Nevertheless, he is a calm-minded person, who is always focused and determined to complete his given tasks. However beneath this facade lies a broken, bloodthirsty, deranged, vengeful, unhinged and cruel man hellbent on a path of vengeance.

Like Toga, Dabi admires Stain and his ideology. He views himself as the one who is destined to fulfill Stain's view of the world, hence his reasoning for joining the League of Villains. However, even though he does not display any altruistic intentions, it appears that he is still just as deluded as Toga as he seems to be unaware of what Stain was actually trying to accomplish. While Stain was trying to bring back the meaning of being a hero, Dabi is simply interested in destroying the current society of humanity as a whole. Despite this, Dabi believes himself to be the true manifestation of Stain's will, believing that "real heroes" are not a thing. It is clear from his actions that he is only using Stain's ideology as an excuse for his actions and that he despises heroes entirely because of how he was raised among them. Dabi commonly shows sadistic tendencies, as he takes pleasure in taunting Pro Heroes and those that seek to be heroes, while attempting to murder them at the same time. He's also observant and ruthless, willing to endanger the lives of others, including U.A. students and even his own allies, while also commonly exploiting a hero's tendency to save people from danger. Despite this, it appears that he can relate to families that have suffered from the society of heroes and villains due to his own pain from Endeavor's actions, as shown by him crying blood while remembering Snatch’s final words, hinting that he may be capable of feeling remorse. Dabi can also come across being very derisive and contemptuous towards his teammates, who he finds crazy as he proclaimed Himiko insane, called Tomura freaky and insulted Spinner's driving skills. While he acknowledges the League's capabilities, he ultimately does not care about any of them, and only values them for their capacity to bring his goals into fruition. Despite this, Dabi ensured that Twice would make it out alive and claims that his death saddened him, though it seems that he valued Twice's abilities to help his goals over any bond the two villains had. Rather than showing any sadness, Dabi expressed a crazed expression of gleeful sadism saying that he hasn't cried since his tear ducts got burned up. Later on, he burns down Himiko's abusive home and gives her Twice's blood so she can transform into him due to her attachment towards him, though when she commends him on his kindness he denies having altruistic intentions and claims that he only burned her home down to mock Endeavor, and likely retrieved Twice's blood due to him finding his Double Quirk useful.