BiggestDE
-blood field projection? like the one used by 'Cadis Etrama di Raizel' in Noblesse. - blood prepulsion? to prepulse MC into a certain place in case MC was in tight position - Kakune like tokyo ghoul. maybe make wings armour tails claw from blood by manipulating the blood density? - MC may also use his ability to manipulate blood to do bloodbending/blood puppetry? - Blood teleportation? if the yuki clan can use the ice surface to teleport then.. why not blood? the idea is to have MC spray lots of blood droplets into the surrounding and using the teleportation to escape, dodge, fight like hiraishin no jutsu. - manipulate oxygen level in MC body to increase stamina, power, speed and also opponent's to induce mental distrubance then combine it into genjutsu then.. it may also be an idea for jutsu???
Since Naruto’s mom is kushina I can assume their home is guarded by fuinjutsu, more so where she hid the seals. Have MC secretly take a blood of Naruto and go to his parents home secretly, then use the blood to unlock any blood-key seals. The mc can then start learning fuinjutsu. MC can then use his experience and create a chakra proximity detector seal and activate chakra reflector seal and apply it in his eyes, reason is he won’t be able to see chakra amplify his eyes with chalra if it’s a constant reflecting seal. With that, MC might even be able to reflect genjutsu and inflict the enemy instead. To not make it to OP, you can make it so that the MC needs a better seal to reflect high level genjutsu, since it will be to op if MC can reflect Tsukoyumi. This is the only way I can think of which makes sense and to not make MC to OP.
If you mix your chakra through your body it will expulse the chakra opponent's chakra that affects your eyes and stop the genjutsu. You can become partially immune if you use the chakra of a tailed beast and mix it in your body to improve your physical abilities and your perception ability but it is only during the use of the chakra. You can't become immune against a genjutsu made by sharingan enven if you have a sharingan(exemple: Sasuke vs Itachi). The only way is to have Rinnegan or Tenseigan. Maybe with the byakugan, I don't know.
Maybe you could do something like the quincy(bleach) skill Blut. It’s supposed to involve blood(I think) and increase their defenses plus they have some crazy abilities. Though I’m personally hoping you add kagune from Tokyo ghoul for offensive abilities. Maybe you could even have him create quinque(ghoul hunter weapons from Tokyo Ghoul) for others to use.