Increase dexterity by 2 and decrease charisma by 2 

You were a humanoid creature in your previous live. your size is medium. 5 to 6ft tall.

Your base speed is 30ft.

Your past life knowledge provides you with common and another language of your choice.

As a creature of the night you can see clearly at night and in dark places. You have 60ft of Darkvision.

You have disadvantage when using a melee weapon to attack with and your movement is halved if wearing medium or heavy armor given that neither the weapon or armor are magical in nature. You have disadvantage on Strength checks and saving throws.

You have disadvantage on (wisdom) perception checks during the day given that the sun is visible. (DM's discretion) Due to the nature of your body you have a Vulnerability to bludgeoning damage. 

You are an undead. As such, you are weak against the divine making have Vulnerability to radiant damage. At the same time, you have a Resistance to necrotic damage. Your nature make healing magic and potions ineffective on you.(you cannot receive hit points from healing magic or potions) Being a skeleton, you lack flesh and organs which means you are not require to eat, drink, breath, or sleep. You also no longer age. You will not drown or suffocate. You have immunities to poison and Exhaustion. Your hollow body allow faster movements. While not wearing armor your movement speed is 40ft.

Due to the way you were form, you have develop a core. Your core lies in the center of your chest and is the control center of your body. the core is the mind and your body is move via mana or magical energy. It maintains your form. As long as your core is not destroy you not will die and will eventually reform. Upon failing all death saving throws roll a d6 to see how many days it takes to reform given that the core is not destroy. Your core act as an arcane focus for spells. You learn the mending cantrip to repair yourself as you reform rather then heal. it does not count towards your number of spells known and does not require material components. You can this feat to Repair(mending) yourself to regain hit points. it can be twice per short or long rest and increase with levels and you regain 1d6 of hit points per use. You can also cast mending as a ritual spell to regain hit points during a short or long rest. you regain hit points equivalent to the rest. Using the mending spell on yourself as a regular action in or out of combat will not grant you any hit points. 

You can withdraw your mana or magical energy into your core to become a pile of bones on the ground. While in this state you will appear motionless to the naked eye and cannot be detected unless by detect magic. in this state you are consider prone and your movement speed is 0ft. You can release your energy from your core to reform back into a skeleton. The location of the core is where you will reform. Your core recalls your bones to reform. However, there is a drawback depending on the distance the core is from the bones. 5 to 10ft - no cost, 11 to 30ft - cost half of your current hit points, 31ft and onwards - cost all of your current hit points but 1(you will reform with 1 hit points). If your hit points become less than 1 you will be force into collapse state and are also incapacitated. it takes one action to collapse or reform using this feat. You cannot cast spells while collapse. However, you can maintain concentration of a spell given that it was cast before collapsing. 

You are able to use metals and others components as a replacement for your bones and gain organs. You can also replace your core using this feat. This process allows you to bypass your weakness as a skeleton. However, this process cost some of your real hit points permanently. (DM's discretion on the amount of hit points and new possible weakness for gaining organs)