Magic Synergist

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

• Increase your Intelligence, Wisdom, or Charisma score by 1, to a maximum of 20.
• When you cast a spell and you are adjacent to another spellcaster with this feat, you can use spell slots of the adjacent caster to fuel your spell, provided they are willing. If you do so, choose one of the following:
  • One of the two spellcaster spend the appropriate level of spell slot for the spell. If it is a concentration spell, the caster must maintain it, and their spellcasting DC must be used.
  • Both spellcasters spend the appropriate (same) level of the spell. The spell is then upcasted 1 level higher than the original cast, and you choose whose spellcasting DC is used and who is concentrating on the spell.