Prefixes suggesting a state of being:
* Un-repentant: Not feeling remorseful or sorry.
* In-repentant: (Less common) Not feeling remorseful or sorry.
Prefixes suggesting an action:
* Re-pentance: The act of repenting again. (Less common)
* Pre-pentant: Feeling remorseful or sorry before committing the act. (Not a real word, but you could use it creatively)
It's important to note that while these combinations are grammatically correct, they may not be widely used or understood.
If you want to express the idea of being repentant, it's usually more effective to use the word "repentant" itself or to use a phrase that describes the feeling of regret or remorse.