The long and short of it is that a soul is allowed to pick a form to be reincarnated as a....DIGIMON!
Only problem is they didn't listen to the full explanation and picked two different Digimon splitting their soul.
Said reincarnation as a Digiegg ended up infront of two of the Elements of Harmony the day after Nightmare Moon.
Now going through life not really understanding how or why. They stick around their Tamers, eh Ponys?
Honestly they have no clue what is going on and is going with the flow.