well i have an idea for naruto c so lets start
1. add wild bijuu that will roam around and will be very strong
2. add the uzumaki clan and have be able to use sealing ninjutsu make it easy for them to learn and very hard to other people.
3.make the uzumaki clan either yourself or an npc and make them seal the bijuu that you found into your body or your family c child.
4.once you acquire the bijuu you will have a skill that will be like super forms in DBC and like when youre level 1 in super you can use 1 tail of power level 2 will be half of the bijuu strengh and 3 will be one tail under full form
5. if your will and mind stats are low once you go to one of the bijuu “forms” you might lose control (make it like 50 combined per super form and configurable) and you will just start to throw attacks at the air until you are out of chakra.
6.add the water fall and cave where you can learn to control the bijuu ( by having a set amount of total attributes also configurable) and gain access to bijju mode who will be like god mode in DBC and you will have the unfriended level and befriended level
7. to gain the friended version you will have to get the first form and then use it for a certain amount of time( configurable ) and once you useud it long enough you will automaticly gain more chakra but not power.
hope this wasnt to long and sorry for bad english
also add suggestions in the commentes