Diamond’s Holy Blast

The user’s prosthetic arm vents draw breath from nearby entities, (including the user) within 15 feet. Each entity takes 1d4 radiant damage. The user can then either heal or damage an entity within 60 feet. For every 2 entities that take damage, the dice upgrade with a cap of a d8 for damage and a d12 for healing.

When no other entities are present, the die is a d6, with two entities it is a d8, then for healing when it’s four entities it’s a d10, and 6 is a d12.

Each of these adds the users spellcasting modifier when rolling to hit. The user rolls to hit for healing as well, with advantage and half the AC for willing creatures.