The human dragon hybrid gets a +3 to charisma ability score. has a weakness to cold damage, taking double cold damage.

They gain resistance to fire.

When they fall below half Hp they can light themselves ablaze dealing fire damage to those who dare step to close. (see damage in seething anger action)

The player may turn into a small dragon for 1 minute (ten turns) at the cost of taking 3D6 damage in this form they get access to flame breath and flight and seething anger damage gets doubled on rolls. 

The player enters dragon form with their Hp remaining plus 10 temp hp. If entering winged transformation would lower them to 0 hp they are instead put into their dragon form with whatever their temp hp is, if they are then brought down out of this form by hitting 0 hp they will revert back into their human form down and automatic fail two saving thrown on their next turn.

Thanks to your elf blood, you have superior vision in dark and dim conditions. You can see in dim light within 60 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

The character may light their blade ablaze for ten turns. They get the same amount of uses equal to their proficiency bonus.

Used to the pain of sprouting wings from your back you can now summon your wings at all times without entering dragon form.