Venom Blade

You call forth elemental poison in the shape of a sword in your hand. This magic weapon lasts until the spell ends. It counts as a simple melee weapon with which you are proficient. It deals 3d8+Spellcasting Modifier poison damage on a hit and has the finesse, light, and thrown properties (range 30/60). In addition, when you hit a creature with this weapon it must make a Constitution saving throw or become poisoned until the end of its next turn. 

If you drop the weapon or throw it, it dissipates at the end of the turn. Thereafter, while the spell persists, you can use a bonus action to cause the weapon to reappear in your hand.

If you perform the spell as a ritual and have an alternate component (a dagger made out of cockatrice bones) the spell lasts for 8 hours and does not require concentration but if you are to roll a Natural 1 on an attack roll the weapon erupts dealing 8d8 poison damage to all creatures within 10 ft. of you and ending the spell. (This feature is setting specific to my homebrew campaign)

At Higher Levels. When you cast this spell using a 5th- or 6th-level spell slot, the damage increases to 4d8. When you cast it using a 7th- or 8th-level spell slot, the damage increases to 5d8. When you cast it using a spell slot of 9th level or higher, the damage increases to 6d8.