Draining shield

You create a 15 ft radius translucent necrotic shield that drains your life force in order to protect your companions.

When you cast the spell you take 1d6 necrotic damage that cannot be reduced by any means, you can keep the spell running by taking another d6 necrotic damage every round you keep the shield up (requires no action).

While the shield is up everyone you choose in the sphere excluding yourself gains the following benefits:

• You add +3 to your AC.
• you gain temporary hit points equal to the damage rolled by the caster (every number rolled you add on).
• Every Spell 5th level or lower has no effect on those within the sphere (including the caster).