The thing about the Avatar line is that their reincarnations is usually the opposite of their predecessor. Knowing how the humble, evasive Aang transferred to the prideful, aggressive Korra, I think that the next Avatar, would be a bit of a showman with a flamboyant personality to try and hide his own insecurities of living up the role of the Avatar.

As for major conflict, it could be a true clash between modern and spiritual. Perhaps the blending of cultures creates a uniform style of bending for all four elements and the Avatar has to learn the true styles of bending the elements in order to fight the big bad of his arc.

>>117112
Was Roku the opposite of Aang or was he the opposite of Kyoshi?

>>117114
He was the opposite of competent.

Mainly Kyoshi.
One of Kyoshi's most steadfast qualities was that she would not tolerate anybody undermining her personally.
She was fine with Chin conquering the Earth Kingdom until he set foot on her turf.
She actually agreed with the Earth King on the Ba Sing Se peasant uprising until he demanded that she obeyed him.
Whereas Roku's greatest failure came about as a result of him failing to put Sozin in his place after numerous warnings which the Fire Lord consistently ignored, undermining Roku's authority.
That right there would NOT fly in Kyoshi's day.

>>117121
How would Aang and Korra handle Sozin?

Energybending and face punching respectively.