Hame Hame no mi or the Rift Rift fruit
Type: Paramecia
Operation: I'll explain this one in a different way, highlighting attacks I can imagine the user using, to give you an exemplary idea of I the fruit's operation.
1. Fissure- This could easily be the user's strongest physically damaging attack. The user rifts the land below him. The user is able to control the size of the rift. Depending on the location of usage, it's effectiveness will vary. Say, it was used in a desert, then the user could create a ravine of quicksand. He could create a direct rift to groundwater tables. Now, the way the actual rift works is that the user is able to hold whatever material he "rifts" in his body, while replacing what he absorbed with the substance he is- "rift", which could be interpreted as void or space.
2. Secco- Now, this is just an example of the wide variety of attacks the user can use after he has absorbed the previously "rifted" substance. Imagine the user of this fruit against Crocodile. If the user can touch Croc, he will easily be able to erase Croc's existence itself by replacing his sand with his void. This means that Croc is technically dead. In this state, the user can become the user of Suna Suna no mi (not technically, but figuratively) being able to use techniques like Secco. He could "revive" Croc by releasing the sand from his body and changing it with "nothing".
3. Paradox- The user touches himself to rift nothing with nothing. Power is lost, but nothing happened. This defies the laws of nature creating a paradoxical energy surge in the user. This enhances the user's capability to insurmountable levels.
So, how about it?