The Rinnegan (Samsara Eye) is a Dojutsu rooted purely in tales and conjecture from a time before the idea of chakra and it's applications for ninjutsu. The only recorded circumstance of the Rinnegan surfacing is when someone known as the Rabbit Goddess gave birth to two sons, hamura and hagoromo otsutsuki, hagoromo was born with the sharingan that he eventually progressed to the Rinnegan. No one knows how to awaken the Rinnegan as it's never happened since thousands of years ago...

The Sage of the 6 paths, are a family of techniques borne from the Rinnegan's occular powers that govern over life, and death in a myriad of ways (each of these paths are represented and rooted in budha as 7 plains governing heaven purgatory and hell. Deva, asura, animal, preta, human, naraka, and outer path)

The Rinnegan allows you to: 

Summon Black rods varying in length, as a bonus action you can summon a single rod to use as a dagger, long sword, or quarterstaff. You are proficient with the rods and it counts as magical and you use your spell casting modifier to attack and damage rolls.

Your dark vision is replaced with true sight.

A unique ability tied to your Rinnegan specifically. (Work with your DM)

And unconscious mastery of all basic magic elements allowing you to empower your spells to overcome resistances to fire, cold, lightning, and thunder, (this only applies to these elements)

Deva Path; you gain access to retraction and repulsion forces through telekinesis. And you gain a flight speed equal to your movement speed as you manipulate your body telekinetically to do so.

Almighty Push as an action this allows you to violently push things away from you in all directions, all creatures in a 30 foot radius around you must succeed on a strength saving throw (DC 8+prof+SC) or take 3d8 force damage and become knocked prone 30 ft away from you. Once you use this attack you can't do so again until you've spent a turn without casting any spells. 

Chaotic Almighty Push, you can choose to expend a spell slot of 4th level to cause a devastating version of your Almighty push, the damage dice Is increased to 6d8 and as a result of the change in destructive power any creatures caught up to 60 ft away from you in a sphere will be knocked back an additional 60 ft away. The damage dice and distance the creatures get knocked away from increases by 1d8 and 10 ft for each spell slot above 4th. Once you use this feature in this way you can't do so again until a long rest has passed.

Planetary Devastation, as an action you focus all of your efforts for 1 minute to create a small gravitational sphere no larger than 5 feet, the sphere then leaves your hands picking up debris all around you until enough debris is collected to make a small planetoid measuring 180 ft all around. Any creatures in a 60 ft radius of the sphere while the sphere is gathering debris must succeed on a dexterity saving throw (DC 8+prof+SC) or become trapped in the sphere. Once the sphere is ready after 1 minute you can as an action cause the planetoid to plummet back into the earth dealing 6d6 fire and 6d6 bludgeoning to those trapped inside and Any creatures in a 60 radius of the plummeting planetoid must succeed on the previously stated Dexterity saving throw or take the above mentioned damage, that area is also now difficult terrain.

Universal Pull, you can as an action pull up to number of creatures no larger than medium equal to your spellcasting modifier if you can see them up to 30 ft away from you. Those creatures must succeed on a strength saving throw or become pulled towards you if a creature succeeds they are instead pulled 15 feet towards you. 

 Asura Path; you can augment your body mechanically.

For 1 minute As an action you can grow another set of arms which you can use to attack with granting you an extra weapon attack.

You can as an action shoot a laser-like projectile from these arms dealing 2d6 radiant damage per ranged weapon attack. Alternatively you can cast magic missle without expending a spell slot up to your proficiency modifier per long rest.

You can cast Jump without expending a spell slot as your body is mechanically altered to do so. Your body reverts back to normal after a minute has passed using this path. You can use this path again after a long rest

Human Path, soul manipulation.

You can as an action grasp at a single target creatures soul by placing your hand on the creatures chest, when you do so that creature must succeed on a DC 8+proficiency+SC Constitution saving throw or die as that creatures soul is ripped from it's body. On a success that creature is unaffected by this attack and instead takes 3d10 Necrotic damage. If you successfully rip a creatures soul out you can learn any 1 piece of information that creature knew during life.

 Animal Path, you can summon one of the following creatures, they use your to hit modifiers and they last until dispelled or are hit a single spell, melee or ranged weapon attack with the exception of the cerberus summon. You can summon one of these creatures again once they die or are dispelled as a bonus action equal to your proficiency bonus per long rest. The summonings are fully under your control and they take their turn after you once summoned.

A giant drill beaked bird that is large enough to carry two people and moves at a 50 ft flight speed. The bird can dive and bite one target dealing 1d6 piercing damage.

A giant rhino that can stampede through most structures and impale enemy creatures. It has 30 ft movement speed and can only use it's action to dash in a line hitting all targets in 10 ft line. Creatures in the area make a Dexterity saving throw (DC 15) or take 1d6 piercing.

A Giant Cerberus that instead grows more heads up to 3 that can move 15 ft, this summoning cannot be killed conventionally and can use it's action to bite in a 15 ft cone with all 3 heads dealing 1d6 slashing per head.

When this creature is summoned you can see through it's eyes as a bonus action and it can travel up to 30 miles away from you if it traveled further than 30 miles away from you the summoning is dispelled.

Preta Path, Absorb magic based attacks and drain the vitality of a creature at close range. You can use either of these features up to your proficiency per long rest.

As a reaction you can absorb an incoming spell by making a spellcasting modifier roll contested by that creatures spell attack roll. If the spell is fire, lightning, or cold damage you have advantage on the roll.

If a creature that can cast a spell is within 5 ft of you you can attempt to siphon their magic for your own benefit. Mske a melee spell attack on a hit you deal 1d12 necrotic damage and on that creatures next turn if they decide to use a spell that targets you it is now made at disadvantage or if they decide to cast a spell on themselves the spell fails. This affect lasts until the start of your next turn.

Naraka Path, Control over the king of hell a large automaton-like object.

The king of hell is primarily used for interrogation, as an action use your spellcasting modifier to grab a hold of one creature within 5 ft of you as invisible chains appear to grasp the target. On a success the creature is grappled and restrained, on your next turn you can ask the creature any 1 question and if they lie to you or refuse to answer you you can roll 4d6 necrotic damage and on top of the damage they lose their maximum hp equal to the number rolled as a result of the invisible chains crushing their soul.

A creature of medium or smaller can walk into the king of hells mouth and as a result they gain the benefits of a short rest, expended hit dice gain a bonus equal to your spellcasting modifier per dice rolled. Both of these features can be used once per long rest.

 outer path, the 7th and final path that presides over life and death.

You can expend one of your hit dice to revive someone from the dead if they were killed In the last 6 hours, doing so takes 10 minutes and that person is brought back to 1 hp as long as that person is not beheaded or died of old age.

If you use this feature more than once every 24 hours you will lose 10 years of your life span. If you can no longer age then you instead lose half of your hit point maximum for 1d4+3 days.

 You can also perform a special ritual to imbue a deceased body with your Black rods allowing you to control the body remotely as you continually flood magic into the body or bodies, you can reanimate up to 6 bodies in this way. Ritual requires an extensively long medical process lasting months to properly create a puppet that you can use by transmitting magic through the black rods, each of these puppets can only use 1 of the Rinnegan's occular powers but they can still use the black rods or use unarmed strikes. Each of the puppets gain half your hp maximum as their own and if you choose to manipulate any of these puppets you are rendered incapacitated. 

Unlike the summonings each of these puppets are visually linked, you can see through all of them at the same time and as a result they cannot be surprised and sneak attacks are ineffective if a puppet is within 60 ft of another puppet. All the puppets inherit your physical and mental attributes.

Notes: Control, Buff, divination