Wildfire Rasengan-glows red and orange and flames burst from it. When it hits they are engulfed in fire chakra and a firestorm is created around the target. If they survive, they have incredibly serious burns all over their body.
Cyclone Rasengan-glows light blue and green and wind blades surround the Rasengan. When it hits it will cut the enemy down to a cellular level but have no backfire on Naruto. If they survive, they'll probably be unable to use chakra or move and have many major cuts to vital parts of the body.
Thunderstorm Rasengan-glows purple and yellow and looks similar to a chidori but more powerful but less powerful than a raikiri. Electricity shoots from it and when it hits, the target shocked and burned. If they survive, they are most likely unable to move from paralysis and have many electrical burns.
Earthquake Rasengan-glows brown and orange and rocks form around it and kinda orbit it. When it hits they are crushed from the pressure of the earth chakra and the surrounding area will have stone spikes and boulders.
Tsunami Rasengan-glows blue and dark blue and waves swirl around it. When it hits they are engulfed in water chakra and drown the target.If they survive, they'll be swept away by the water.
Tempest Rasengan-Cyclone and Tsunami Rasengan combined. Trapped in a vortex of wind and water chakra.