Spell Mastery

When you take this feet, choose a school of magic. You've learned to manipulate the power of this spell school to your advantage, using your mastery of it to empower your attacks. You gain the following benefits:

• On your turn, when you score a critical hit with a spell of the specific school you chose or reduce a creature to 0 hit points with one, you may immediately cast a cantrip.
• Before you make a spell attack, you can choose to take a -5 penalty to the attack roll or to your spell save DC. If the attack hits, you add +10 to the spells damage initial damage.