You conjure a magical dark bow in your hands. For the duration, you gain proficiency with Shortbows while firing from this bow and you do not require ammunition. Additionally, every creature hit by an attack with this bow must succeed on a Constitution Saving Throw or become poisoned until the end of their next turn. 

For each level of spell slots used to cast this spell beyond 2nd, the duration of the poisoned effect increases by 1 round. Additionally, if you cast this spell at 4th level or higher - you gain the Extra Attack feature while firing from the bow.