The master of elemental transmutation (Warning: expects high spell knowledge)
Design Jam Preserve.
Level 3
Transmuter’s Prism.
When you roll initiative, choose a type among Fire, Ice, Lightning, Radiant, or Necrotic. ALL damage you deal becomes the chosen type until you choose another type. Then, you may cast a cantrip from that Spell School for free.
Transmutation Adept.
Gain the Elemental Transmutation Spellshaper ability. You can spend 0 mana to use it on your cantrips.
Level 7
Prismatic Deflection.
(1/encounter) Free Reaction: cast the Defend Spell of your Prism’s chosen type for free (you may upcast it as normal).
Transmuter’s Touchstone.
Learn 1 Cantrip and 1 Utility Spell of your choice from among Fire, Ice, Lightning, Radiant, or Necrotic Spell Schools.
Level 11
System State.
Whenever you Assess (after resolving it), activate Transmuter’s Prism for free. (1/encounter) Your Assess gains advantage.
Level 15
Prismatic Absorption.
You are resistant to damage of your Prism’s chosen type.