By flying around as a ghost, you learn to deftly cruise around, making you very nimble. Your Dexterity score increases by 2.

you are a literall ghost, you do not age at all.

You are a smoll pokemon, your size is small.

You can float around at a decent speed, after all you have been doing it a long time now.

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.

Using ur ghostly form, u cast a intimidating look to other people. You get proficiency in the Intimidation skill.

Being able to float around, without a sound, You gain proficiency in the Stealth skill.

in addition, you get access to the spell disguise self once per long rest, without using a spellslot.

Your ghostly form has become weak to all thats radiant. You have vulnerability to radiant damage.

Astonish deals 2d4  and has a chance of causing the target to flinch (target must trow a CON save dependant on  8 + WIS modifier + CHAR modifier to determin the flinch state.) if the target flinches, they get a disadvantage on attack rolls.

You can use this spell 3 times a day as a 1st level spell, 3 times per long rest. this does not cost a spell slot.

At higher levels: at character level 5, increase the damage roll to 3d4. gain aditional dice at at 7th, 11th and 15th level.