Spell Surge Master

You cast spells wildly channeling dangerous surges of magical energy through them. The resulting magic is unwieldy and can easily go astray but when it hits it is substantially more effective. You gain the following benefits:
• Before you make a cantrip attack, you can choose to take a -5 penalty to the attack roll. If the attack hits, you add +10 to the attack’s damage.
• On your turn, when you score a critical hit with a single target spell attack or reduce a creature to 0 hit points with one, you can use the resulting spellsurge to make one cantrip spell attack against a creature within 10 ft. as a bonus action.