Naruto to Boruto: Shinobi Strikers has a lot of different ninjas in it, with a lot of powers at players' fingertips. This includes, with proper training, the ability to mix and match those powers as different jutsus and tools, meaning there's an incentive to give attention to underrated characters.
However, some of the best powers are directly analogous to the strongest powers in the show and manga. One of these includes the Rinnegan, one of the most powerful eye-based powers in Naruto. To get the Rinnegan's associated powers in Naruto to Boruto: Shinobi Strikers, players must follow some very specific steps.
To unlock the Rinnegan, players must unlock the powers associated with it. There are several of these and they are scattered around a few different ninja masters, but fortunately not that many. After all, there are few characters in the show that ever mastered the power of the Rinnegan. Plus, even though it's an evolution of the Sharingan, players don't have to unlock the Sharingan in Shinobi Strikers to unlock the Rinnegan.
Once players equip a jutsu that requires the Rinnegan, their custom character can officially have the Rinnegan eyes, either one or two depending on their other jutsus.
The easiest master to learn Rinnegan jutsus from is Pain, ostensibly the strongest member of the Akatsuki and their leader. He's not unlocked at the start of the game, but the method to unlocking him is pretty easy: players must reach the second mastery level with Konan.
Konan is Pain's direct lieutenant so this makes sense and has unique jutsus herself. Reaching the first mastery level with Pain unlocks Almighty Push, a Rinnegan ability. It's not the only one of course, but simply reaching that first mastery level with Pain is enough to officially earn players the power of the Rinnegan.
Pain gives Rinnegan techniques beyond Almighty Push, including Almighty Pull and Planetary Devastation, a Secret Technique (Shinobi Strikers' take on ultimates). Sasuke as an adult from Boruto also gives a Rinnegan technique, but he's DLC, which some players can't afford. It's a shame too since he's how players get their hand on some of Sasuke's best jutsus.
No matter the master players use, they will have to put some time into that character. It can be a bit of a grind to get the really good abilities, but a fun grind if players like the game in the first place. Like an entertaining anime filler arc, the real prize is on the other side, but the ride to the Rinnegan is still worth experiencing.
Naruto to Boruto: Shinobi Strikers is available on PC, PS4, and Xbox One.