Apollo is the son of Princess Celestia and Discord
Apollo is Creative, Mischievous, Dramatic, Fatherly, Proud, and Nurturing he has a love for the arts from art to music, from theater to poetry he encourages ponies to tap into their inner artist and even showcased in many plays and even wrote a few, unlike his mother he CAN act and is quite good at it.
He is also been known to be rather dramatic and has been jokingly called a drama king which he hates, being the son of two of the most powerful magic users his powers are unpredictable but has learned how to control them to an extent but at times he has to wear a special ring on his horn when he has a magical outburst.
Of course he hates the ring but he isn't given much of a choice, despite it all he does want to be a just but caring ruler like his mother. But also has been known to play hookie from duties with Discord, which does not amuse his mother and has gotten in trouble many times for that.