Oppenhammer

An odd hammer bathed and seething in radiation. Its spills energy and sickness and is said to hold the power to destroy cities.

You gain a +3 bonus to attack and damage rolls made with this weapon. As a bonus action you can activate the hammer. While activated, when you hit with an attack roll using it, the target takes an additional 3d12 radiant damage. Any creature that takes this damage can't regain hit points until the start of your next turn.

At the start of each of your turns while the hammer is activated, you take 6d12 radiant damage. This damage ignores resistance, immunity and cannot be absorbed.

While activated, you gain the following abilities:

Fat Man. You can choose to swing the hammer directly down to your feet. You cause a massive explosion centered on you that creates a 20-foot-deep, 200-foot-radius crater on impact. Any creature in that radius must make a DC 20 Dexterity saving throw, taking 30d10 radiant damage on a failed saving throw, or half as much damage on a successful one. All structures in the radius take this damage without save. This damage ignores resistance. You can use this once per long rest.

Little Boy. You can choose to swing the hammer directly down to your feet. You cause a massive explosion centered on you that creates a 20-foot-deep, 200-foot-radius crater on impact. Any creature in that radius must make a DC 20 Constitution saving throw, taking 30d10 radiant damage on a failed saving throw, or half as much damage on a successful one. All structures in the radius take this damage without save. This damage ignores resistance. You can use this once per long rest.

Radiation. You emit a bright light and aura of sickness and death up to a 30-foot-radius sphere centered on you. This light spreads around corners. When a creature moves into your light for the first time on a turn or starts its turn there, that creature must succeed on a DC 20 Constitution saving throw or take 4d12 radiant damage, suffer one level of exhaustion and become irradiated. On a success, they only take half as much, don't suffer a level of exhaustion and aren't irradiated. This damage ignores resistance and cannot be absorbed. Being irradiated makes it impossible for the creature to benefit from being invisible. The radiation and any levels of exhaustion caused by this effect go away when they their next turn outside your light. You are immune to this effect.

 

Proficiency with a Maul allows you to add your proficiency bonus to the attack roll for any attack you make with it.

Notes: Bonus: Magic, Damage: Radiant, Heavy, Two-Handed, Topple