Explanation: Elagabalus was a Roman Emperor of the early 3rd century AD who is infamous for their (as their gender identity is a matter of perpetual debate) misrule - perhaps unsurprising considering they were brought up in Syrian traditions, and then given ultimate autocratic power over a position which prioritized Roman norms, all at the wisened and restrained age of 14. They had... no end of scandals, both violating cultural taboos and genuine misrule, and in general seemed to take to supreme power as one might expect a horny teenager to - ie not well.
Severus Alexander was even younger upon ascension to the position of Emperor (both very much outliers) at the age of 13, but unlike the headstrong and independent Elagabalus, was a gentle and mild boy who listened to the authorities around him, especially his mother (who was a consummate political animal). For this reason, he's generally considered a decent, if not outstanding, Emperor, who ruled in accordance with the Senate's wishes, had few scandals, and was generally, seemingly, a sweet and intelligent (if meek) lad whose favorite entertainment was watching baby animals play. Mama's Boy > Wild Child, it would seem - at least for purposes of rulership!
Severus Alexander ruled for 13 years, which was a good clip, before the army overthrew and executed him for his lack of militancy - he sought to pay off a barbarian tribe which had rampaged through the home provinces of many of the Legions' recruits. For understandable reasons, the Legions preferred vengeance to paying off the people who had destroyed their homes and families.