Future Trunks might be able to time travel (and has done so twice as of Dragon Ball Super) but he can’t his own transfer powers to his namesake from the present day like the titular hero from the manga Ragna Crimson can. And that’s not even mentioning everything that Ragna can do.
In Dragon Ball Z, Future Trunks comes from a world that has been destroyed by Androids 17 and 18. He first travels back in time with an antidote to give to Goku, who died in the future from a heart disease. The time traveler hoped that if Goku survived the fatal heart disease in the present day, then the horrible events from his world wouldn’t come to pass. Ironically, Future Trunks doesn’t help much besides providing Goku with the antidote. He does, however, play a much more crucial role when he returns in Dragon Ball Super to fight Goku Black and Future Zamasu.
In Ragna Crimson, the titular hero is a worthless fighter who spends almost every waking hour accompanying the strongest dragon hunter in existence, a small, young girl named Leonica who goes by Leo. Ragna cares deeply for Leo and wants nothing more than to be by her side, even if it means that he can’t become a more skilled hunter. And even though he trains, the only reason the he does is not to get stronger but because he’s terrified that him being weak could one day prevent him from being by Leo’s side. Additionally, he only trains when Leo is sleeping so as not to disturb her rise to the top.
In the series, Leo is portrayed as an undefeatable hero who always wins with relative ease, but Ragna begins having visions where a mysterious man foretells Leo’s doom, shaking his resolve in Leo’s ostensible invincibility. The possibility of her demise unfortunately comes to pass soon afterward when a Superior Drago confronts the young girl and easily defeats her. Before dealing the finishing blow, Ragna is confronted once more by the strange mysterious man who reveals that he is Ragna from the future. Ragna learns that Leo is killed in the future and that, broken hearted, he spends years becoming the most powerful dragon hunter of all time, easily surpassing what Leo had achieved when she was still alive. But his power and stature means nothing to Ragna’s future self because the only person he cared for is now dead. So future Ragna bestows upon his past self all of his powers to save Leo’s life.
In a display of truly phenomenal writing, Ragna receives more than his future self’s abilities. He gains all of his namesake’s memories and feelings. So even though Leo is alive in his time, once the procedure ends Ragna becomes overwhelmed with an interminable sadness as though she were actually dead. So even though Ragna is able to slay the superior Dragon easily, the most touching moment transpires when he runs to Leo and holds her in his arms due to the overwhelming feelings that he received from his future self.
On the surface, Ragna Crimson‘s titular hero from the future has a more effective way of helping his past self than Dragon Ball‘s Future Trunks. Trunks not only fights on his own rather than teaming with his younger self, but he usually fails. Meanwhile, Ragna from the present day is able to slay the creature who would have killed his beloved Leo instantaneously, thanks to his future self. Additionally, the emotional impact in Ragna Crimson is much more pronounced than it is in Dragon Ball as Future Trunks’ suffering is greatly marginalized in the series. Manga readers can only experience what Future Trunks went through in his own time by watching the History of Trunks movie. At least, Future Trunks interacts with his past self in Dragon Ball Super, though they are unable to connect on a deep level besides arguing about girls. Hopefully, both versions of Trunks will become more intertwined in each other lives’ as the series progresses like the titular heroes are already in Ragna Crimson.
