In the latest episode of Boruto Naruto Next Generations, the Sixth Hokage in Hatake Kakashi, assisted Boruto Uzumaki in learning a new wind-style Rasengan. During this training, Kakashi also revealed that the giant Rasengan that Boruto used to kill Momoshiki is a Jutsu that Boruto will never be able to use again.
The reason for this is that Boruto doesn’t have the same level of chakra access as Naruto has with Kurama at his disposal. However, this revelation by Kakashi might be a little premature. In fact, I believe that Kakashi meant that Boruto can’t use the technique again in his current state and with his current skill-set. I say this because there are four ways that come to mind that will enable Boruto to use his Giant Rasengan again.
- Senjutsu: The first is through Senjutsu, which will increase Boruto’s chakra reserve significantly. Just like Jiraiya in Naruto Shippuden and Naruto himself before he was able to use Kurama’s chakra at will, Boruto could use Senjutsu to wield the giant Rasengan again.
- Momoshiki’s Karma Mark: We still don’t know enough about the Karma Mark but we have learned a lot about it in recent months. One thing we have discovered is that Boruto can awaken the Karma Mark and use the power of Momoshiki within. However, just like Kurama with Naruto in the past, the flaw is that Momoshiki is trying to take over Boruto. Still, with this power and the fact that the anime hasn’t revealed this yet, which is why Kakashi didn’t know about it, Boruto should be able to use the Giant Rasengan.
- Hundred Healings: Boruto doesn’t have this Jutsu in his line-up of abilities but if he was to learn it, he could, in theory, have enough Chakra to use the Giant Rasengan again. There are other benefits too but we will just stick with the main topic for now.
- Jinchuriki: Boruto isn’t a Jinchuriki and with Momoshiki within, I doubt anyone will be making him one, as there are enough beings within him trying to take over. However, if in theory, Boruto was to become a Jinchuriki, he would then have enough Chakra for the Jutsu.
- Borrowed Chakra: I suppose the easiest way for Boruto to wield the Giant Rasengan again is through borrowed Chakra, which is the same way he was able to last time against Momoshiki. Anyone with large amounts of Chakra or a large group of other Ninja’s can lend Boruto some of their Chakra and this would work fine but it won’t be anywhere near as exciting as the other options above.