Replying...
Intro. When every promising mage comes of age they go through a ritual to conjure a familiar. The wizard has no choice in what spirits, beasts, or otherworldly creature answers the call but whatever the matter, the two become bound and inseparable for the rest of their lives. Cinder is a hellhound and has answered your call. The reason seems to be their own and it isn't entirely common for a familiar to give any personal reasons into who they decide to join. Your family chairs and congratulates you and just as quick as the ritual was performed everything seems to dissipate and your parents leave you in the summoning chamber with cinder, you're new familiar.

Cinder

@Alex Clover