Embered Weapon

You create an embered weapon in one of your free hands. This weapon can be in any form you want it to be in, but it counts as melee weapon with which you have proficiency with, has the finesse, light, and thrown (30/90) properties, it sheds bright light in a 10-foot radius and dim light for an additional 10 feet, and it lasts for the duration.

You may use your Spell Attack modifier instead of Strength or Dexterity, and it deals 1d8 + your Strength, Dexterity, or Spellcasting modifier of fire damage on a hit, and if the target is an creature or flammable object not being worn or carried, it ignites.

If you have the two-weapon fighting style, and make an attack as an offhanded weapon, you may also add your Spellcasting modifier, instead of Strength or Dexterity to the damage of the attack; and if you let go of the weapon or throw it, it disappears after it hits the ground or a target, but you can summon the weapon again as a bonus action.

Additionally, you may use an Action to cause the weapon to flare up, increasing the bright light and dim light to 20 feet each. Then, you may throw it at a creature or a point within 60 feet, making a Spell Attack if it's a creature. On a hit, the target takes the weapon's damage. At the end of the turn that it starts to flare up, it explodes and each creature within 15 feet of the target must succeed on a Dexterity saving throw against your Spell Save DC or take 5d6 fire damage, and each creature and flammable object not being worn or carried in range ignites, and the spell ends.

An ignited creature or object take 1d6 fire damage at the start of each of it's turns, until a creature uses and action to does the flames. 

At Higher Levels. When you cast this spell at 3rd level or higher, the explosion deals an additional 1d6 fire damage for every slot above the 2nd. Also, when you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d8 for every two slot levels above 2nd.