You tap into your deep wellspring of magic to invoke Chaotic Surge as a Bonus Action to enhance to power of the next spell that is casted. The next spell you cast using a spell slot is casted one spell level higher. If the spell that is casted at a spell level you do not have access to, you will suffer 1 point of exhaustion after a number of minutes equal to your Constitution Modifier (minimum of 1).
After having triggered the effect of Chaotic Surge, your magic becomes "Unstable". At the start of each of your turns, you must roll a d20 (on an ever increasing DC determined by your DM), on a failed roll you must then roll once on the Wild Magic table. Once you roll on the Wild Magic table your magic stabilizes. If you roll a 20 while under the effects of being "Unstable", your magic will instantly stabilize and you will regain use of Chaotic Surge one additional time. If you use this ability in this way before taking a long rest, you will then gain 1 point of exhaustion after a number of minutes equal to your Constitution Modifier (minimum of 1) per use of Chaotic Surge.
Once you use this spell, you must finish a long rest before you can use it again.