Name: Flamerang
Item: boomerang
Rarity: very rare
Attunement: yes
Usage: You have a +2 bonus to attack and damage rolls made with this magic weapon. On a hit with this weapon, the target takes an extra 3d4 fire damage. Fire damage from this weapon bypasses resistance to fire. On a successful hit you can choose to have a 3rd level fireball go off on the target. Once this item's feature is used it can be used in this way until the next dawn. (set DC 16)

thoughts? iv been working on new magic weapons for the ones that dont have alot or alot of good ones 

That’s not Very Rare. That would be at least Legendary, at least. It’s a thrown weapon that essentially has the benefits of a flame tongue combined with a weapon, +2, and it negates fire resistance, and it can pop a fireball once per day too. At least Legendary, bare minimum.

I mean balance that against the downside that it's a boomerang...

I'm kidding, but only sorta. Take off the fireball part and I still don't think it outcompetes any other options at the point you're getting VR stuff.