Curse of the dying

The user amasses necrotic energy from their curse to emenate a mass of energy out of the users arm. The spell can only be cast when using Arm of the dying.

A surge of necrotic energy blasts out from the users palm, dealing 3d6 in a 10ft. wide cone. The pain caused from this spell makes the user loose 20% of its hp on cast. 

The spell can be powered up with 1d6 per 10% consumed max health. The spell can't be cast with a health cost of less than 20% hp.

The spell has a range of 10ft., but gains 2.5ft in range for each added die.

If the spell breaches a 50% health cost the Arm looses 1 duration. After casting this with a health cost of 50% or more the health cost for the next use of the spell is doubled. If the user casts the spell while the health cost is doubled AND breaches a 60% health cost, the Arm breaks (after the spell has been cast).

 *The die changes to a d8 at level 5, a d10 at level 11 and a d12 at level 17.