User is tied to a demon as their child

Pros:
-user learns about all powers they can comes across
-user can be granted abilities by a demon parent
-user is guided and trained by demon parent through their life
-when child is on death's door, demon can send soul to true paradise
-demons are actually incredible parents 98% of the time (most issues they keep away from a user)
-demon parent can possess a user to protect them
-user can go on trips with demon parent
-demon parent can communicate with human parents
-demon is tied to family name so they get to see their great great great great grandchild grow

Cons:
-user may find that human parents want to limit contact with demon parent so they are the only parental figures for the user (why would you tho?)
-demon fades when child is 18 and can only observe after that
-if user dies, demon is forced into their body with powers, living the user's life
-user takes power form demon who grants it
-demon can only watch family grow from a distance

Weakness: death with demon in the body
Demon is forced to hell for really harsh random punishment for breaking the pact and torturer is a corrupted user who is destroyed mentally. Possession must be cautiously done for this reason.

Quirk can be passed on via DNA samples (All Might method)