Magical Overload

Ability to cast spells.

You must use one spell slot of your highest spell level to cast or prepare a spell of a lower level. This spell slot may be used to cast or prepare any spell of any level lower than your highest level, effectively causing you to lose one of your highest-level spell slots to gain one of a lower level. For example, a 6th-level sorcerer would lose the ability to cast one 3rd-level spell per day, but would gain the ability to cast one additional 0, 1st-, or 2nd-level spell instead. This flaw always affects your highest spell level and changes the spell level it affects as you gain levels.

You have difficulty controlling your most powerful magic, being more comfortable with more familiar, lower-level spells.