cloud of poison daggers (revised)

You shoot daggers in a cube 5 feet on all sides, all aimed at a point you choose as long as it is in range. The creature takes 4d4 slashing damage and 1d4 of poison damage when hit. If they succeed  their DEX saving through, they take half slashing damage. You take poison damage no matter what. Every two spell casting levels, slashing damage is rolled with the one dice type higher. Level 3 = 4d6 and 1d6. Level 5 = 4d8 and1d8. Level 7 = 4d10 and 1d10. *Level 4d20 and 1d20. There in no save for the fast acting poison unless they are immune to poison damage.

* Level 9 is the exception of the rule above.