Explanation: Marcus Aurelius was an Emperor known for his philosophical musings. He was a dutiful man, and his private journal, his Meditations, still exist today. They're an excellent read, a good bit of insight into Greek-originated Stoic philosophy as it existed in the 2nd century AD Roman Empire.
Caracalla was a... rather vicious fellow who, like many Emperors, dreamt of conquering Persia. Unlike many Emperors, Caracalla went so far as to imitate Alexander in style and travel routes, supposedly even equipping over 10,000 men in the Macedonian style (a style of combat which hadn't seen warfare since it was, uh, dismantled by the Roman Legions). He died before ever setting foot in Persia, assassinated by his own men. Probably a good choice, all things considered.
Elagabalus was a teenager who was the high priest of the Syrian Sun God and, at the mature and stable age of 14, became Emperor of Rome by the scheming of their mother and grandmother. It didn't go well, as one might expect. Other than Elagabalus having an unusual (possibly transfemme or NB) gender presentation (something the Romans, who were obsessive about masculinity, did not approve of), they also tried to reform the long-standing religious system of Rome in very... nonintuitive ways. Like replacing Jupiter with the Syrian sun god. And bringing along a black stone to worship as the incarnation of said Syrian sun god.
... don't let your teens become emperors, parents. It never ends up well. Talk to them about the responsible age for rulership before overthrowing the previous government of your polity ๐