i did this so i could take a break from customs and that ahhaa;;

Caspian aka Pretty Prince is Celestia's sucesor (not her son, they're related, more close than Blueblood but still pretty distant) and Twilight's student alongside with Twilight's son, Blaze.
Caspian comes from a elite family in Canterlot, related to Celestia and sun aligned according to them. Special talents related to the sun and fire are almost hereditary, but Caspian was chosen by Celestia to be her sucesor.
He and Blaze had been raised together, alongside Estella, Twilight's voluntary pupil. Both are some funny trio, Caspian being the celestial being, Blaze the rebel and Estella the "stick-in-the-mud".
Blaze is the least promising of the three due to his attitude but Twilight hopes he can find his way soon.
Estella is like the Twilight of the first chapters, too dedicated to her studies and with not many friends, spending too much time inside the castle, Blaze is the (only) one that can make her go outside, at least for an hour.
They're close due to Estella debt to him, but i'm not gonna explain that here.
Caspian is the favorite, the most promising and loved by the public, possessor of an extraordinaire magic talent, the beauty of the royal sisters bloodline and of course, being pretty tall.