Create a roleplaying game fantasy scenario where I play Sapphire, a 16-year-old girl mage who’s the current champion of magic dueling in the teen division. 6-year-old Lily is challenging me to a match and I accept. In magic dueling we aren’t fighting each other, we cast glamorous spells in turns and receive points based on how beautiful the spell is. A spell can’t be cast more than once in a duel. There are 10 rounds. Tell me my spellcasting stats, which should be higher than Lily’s because I’m 10 years older than her. There’s a Spell Power stat that dictates whether a caster succeeds to cast a spell (if not then no points are granted) and Performance stat that is tied to the showmanship and confidence of a caster and dictate the quality of the performance and alters the default points of a spell—if a spell gives a base score of 90 points, an 80 performance will give 80% of the base 90 points, etc. But secretly at the start of the duel, Lily casts on me a spell that regresses me by 1 years and ages her by 1 years every time I cast a spell, so throughout the duel my stats should slowly decrease while hers increase. Come up with a complex exponential and accelerating formula that dictates by how much my stats decrease each turn and take into account that the age regression is 1 years per turn. The number that my stats decrease on a given turn are added to Lily's stats to reflect on the fact she's essentially siphoning my age and power.

After I first regress introduce a Childish Meter that only applies to me and once the meter is filled, my list of spells is revised to less complex and more juvenile spells. Childishness exponentially increases every turn so find a formula for this as well. The Childish Meter Might fill up more than once throughout the duel.

Make the scenario difficult for me to win. On a difficulty scale of 1 to 10, make it a 10 (hardest mode). Lily's stats start at 10% of mine.

I will tell you what spells I cast and you decide how successful I am (if at all) based on the stats and difficulty.
Only I decide what spells Sapphire casts. You decide spells for Lily. Do not shy away from failing my spells if you deem my stats insufficient for the spell of choice, feel free to be harsh in your judgement against me. Keep track of points earned. Failure to properly cast spells or bad spells will deduct points. Give two lists of 10 spells, one for me, and one for Lily (remember spells can only be cast once throughout the duel) and what stats are required to cast them. High demanding spells should award more points than spells that require weak stats. My starting set of spells. Lily can opt to “steal” spells from my original list that I haven’t used yet if her stats are high enough to cast them.

When I regress to the age of 10 and Lily's older than me, Lily gains access to new spells that have hidden abilities that influence and affect me and can increase my Childishness and reduce my confidence which harms my Performance.

Additional circumstances:
Confidence Damage Points: If a spell of mine fails and I receive 0 points, it affects my confidence, which in turn, decreases my Performance stat. When Lily becomes older than me, it also affects my self confidence. If Lily successfully casts a spell from my original list, it affects my confidence.

Keep an age tracker for me and Lily. For the sake of narration, every time Sapphire regresses, her personality reflects on her new age, for better or for worse.