Elemental Master

Prerequisite: Elemental Adept of the same element and be of 14th level or higher to take this feat

When you gain this feat, you gain the following benefits:

• Spells you cast ignore immunity to chosen elemental damage, they are treated as resistant instead. In addition, when you roll damage for a spell you cast that deals chosen elemental damage, you can treat any 1 or 2 on a damage die as a 3
• You gain resistance to the same chosen element.
• You can select this feat multiple times. Each time you do so, you must choose a different damage type.
• When casting the selected element the following effects take place, these effects do not stack with pre-existing conditions the spell may have.

• Fire

  When you cast a spell that deals fire damage. You can choose one creature, that takes damage and failed the initial save from the spell, it catches fire. The creature is on fire takes 1d10 fire damage at the start of their turn.

  Cold

  When you cast a spell that deals cold damage, you can choose one creature damaged by that spell their movement speed is reduced to by 10' until the end of their next turn.

  Lightning

  When you cast a spell that deals lightning damage, you cause the lightning to hamper their attacks causing them to attack at disadvantage till the end of their next turn.

  Acid

  When you cast a spell that deals acid damage. After dealing damage, the weapon takes a permanent and cumulative −1 penalty to damage rolls. If its penalty drops to −5, the weapon is destroyed. If the object effected is either metal armour or a metal shield being worn or carried, it takes a permanent and cumulative -1 penalty to the AC it offers. Armour reduced to an AC of 1 or a shield that drops to a +0 bonus is destroyed.

  Poison

  When you cast a spell that deals poison damage, you can choose a number of creatures equal to your proficiency bonus, on a failed save these creature are effected by the poison condition until the end of their next turn.

  Thunder

  When you cast a spell that deals thunder damage, each creature that takes damage from the spell is pushed up to 15ft away from you or knocked prone (your choice).