Your Strength and Constitution increases by +1 and you increase any stat of your choice by +1

Demons do not age but can look younger or older after being reincarnated, it all depends on how they see them selves.

Most demons walking speeds are 30 ft.

You can speak, read, and write Common and Infernal

You have immunity to disease and resistance to fire and necrotic but vulnerability to cold.

Because of your reincarnation in to a demon, you gain the ability to infuse your hellish soul to any melee weapon of your choosing and inflict 1d6 fire damage to a creature of your choice but you’ll to take half the number you just rolled points of normal damage.

At Higher Levels. If you cast this spell using a 3th level spell slot, you deal 2d6 Fire damage to 1 foe. If you use a 5th level spell slot, deal 3d6 Fire damage If you cast this spell using a 8th level spell slot, you deal 4d6 Fire damage to foes within 5 feet of each other except yourself. 

During your reincarnation, you began to change/mutate in something you knew to be unnatural. Here are your choices on what type of demon you want to become.

NOTE: I might add more mutation options in the future

Most Demons are evil and live or destruction and death, But there are those who can become neutral or even good for those who seek or have found enlightenment.

A normal demons neutral size are medium but the most crueler and more powerful demons can come in different sizes.

Because of the sins you have committed in your past life, you have been marked by the reincarnation process. Here are your options