Versatile Magus

This feat is created by Nedrapter for use in his Land of Arda campaigns, and are balanced to the hardcore nature of them. 

• As a bonus action, you can swap the damage type of your next spell as following:
  • Radiant <---> Necrotic
  • Fire <---> Cold
  • Thunder <---> Lightning
  • Acid <---> Force
  • Poison <---> Psychic
• Whenever you damage a creature with a damage type that it is vulnerable to, you gain temporary hit points equal to your highest class level.