WARNING: The following contains spoilers for Season 5, Episode 12 of My Hero Academia, now streaming on Funimation, Hulu and Crunchyroll.
My Hero Academia often delves into Shoto Todoroki's difficult relationship with his father, who married his mother in a Quirk marriage with the hopes of having children who could wield both fire and ice. Endeavor was extra hard on Shoto -- his only child capable of doing so -- to shape him into the most powerful hero. After his years of abuse and family turmoil, the boy exclusively used his mother's ice Quirk in an act of defiance against the fire side represented by his father.
Todoroki first used his fire side at the Sports Festival after Deku encouraged him to utilize all of his abilities because his powers are his own. As Todoroki has been actively attempting to improve his relationship with his father, he's also learning to accept his fire half more and more. Now, in Season 5, after years of deliberately suppressing his father's Quirk, the young hero is finally tapping into Endeavor's firepower to master his most devastating combo move: "Flashfreeze Heatwave."
Since receiving his encouragement at the Sports Festival, Todoroki has admired Deku's positivity and determination. Watching him improve and master his own Quirk after initially struggling has inspired Todoroki to push harder as well. In My Hero Academia Season 5, Episode 12, he praises Deku's new capabilities before claiming the two of them aren't that different right now. Acknowledging his own limitations, he admits he isn't good enough at handling his Quirks and needs to aim higher.
To really drive home Todoroki's newfound motivation to master his fire Quirk and overcome his past, he asks his father to teach him more about Flashfire. This pleases Endeavor, who wants to restore his relationship with his son. The gradual acceptance of his father and the drive to utilize his fire Quirk sets Todoroki up for becoming a new and improved hero, allowing him to reach greater heights than ever.
As the students of Class 1-A prepare a surprise party, Todoroki and Bakugo undergo their last day of remedial courses to earn their Provisional Hero license. While on patrol, villains show up riding on a tidal wave that sweeps up people and their belongings. Todoroki uses ice to freeze the entire wave and the villains, initially refraining from using any of his fire Quirk. However, the villains are powerful and claim that ice won't be able to stop them, causing Todoroki to prepare for a violent move he has "no choice" but to use.
Todoroki performs Flashfreeze Heatwave, which utilizes his ice and fire Quirks simultaneously. The fire in his ultimate combo move disables the villain's carbonation Quirk (carbonated water turns flat when it's heated up). Bakugo recognizes the move from the Sports Festival but Todoroki shows better control this time, holding back enough to minimize any damage. With a newly controlled and perfected move, Todoroki increases its effectiveness while also reducing the hazardous risk to bystanders. This powerful combo helps Todoroki and Bakugo prove that they were right to earn their Provisional Hero license, finally joining the rest of their classmates.
With the mastered Flashfreeze Heatwave now out in the open, My Hero Academia fans will be excited to see what Todoroki has in store for the future. With his newfound motivation to perfect his father's fire Quirk, there are no limitations on what he can achieve.
