Humo

Humo was born, along with his brother, from an arranged marriage. For the sole purpose of sire more ponies with powers (as their parents also had them).
He and his brother were taken to an orphanage where they would learn to control their abilities.

His experience there was not a pleasant one.
He was not very friendly, almost always ended up scolded or punished for bad behavior, besides being mistreated by his caregivers, fighting with his brother and having almost no friends.
All this was forging his closed and pessimistic personality.
He developed an unhealthy taste for burning things (small at first) and annoying others as a way to release stress.