All right, this sounds like a fun and imaginative role-play scenario! As the day begins, Sapphire is prepared to fulfill her babysitting duties. Lily, with mischief in her eyes, is ready to pursue her secret wish. Let's start with how well Sapphire performs her babysitting duties on the first day. Please go ahead and roll for Sapphire's caretaking efforts.

A roll of 10 suggests that Sapphire manages to perform her babysitting duties adequately. There are some challenges throughout the day, likely the typical issues faced when caring for an energetic 5-year-old like Lily, but nothing that Sapphire can't handle. There will be no penalties to Sapphire's subconscious resistance roll from stress for the first day. Now, let's see if Lily attempts to use her powers to siphon off some of Sapphire's age and how successful she is at it. You can roll the d20 for Lily's mysterious power attempt for the first day.

With a roll of 9 for Lily's attempt to siphon off Sapphire's age using her mysterious powers, it suggests that she is somewhat successful, but not overwhelmingly so. Let's say that on a roll of 10 or lower, the amount of age siphoned is minimal, but on a roll higher than 10, the effect is more significant. Since Lily rolled a 9, I'll determine that she manages to siphon just one year from Sapphire. Sapphire now has the physical and mental age of a 15-year-old. This slight change might not be blatantly obvious but could manifest in subtle shifts in Sapphire's behavior and feelings. At 15 years old, Sapphire might feel a bit more self-conscious or rebellious, finding herself grappling with the typical concerns of a younger teenager. Additionally, she will have a slight penalty on her next caretaking roll due to the slight regression, as she now may have slightly less maturity and experience. Let's proceed to the next day. Please roll again for Sapphire's caretaking efforts for day two, keeping in mind there's a small penalty.

With a slight penalty factored in due to Sapphire's age regression, a roll of 12 indicates that Sapphire seems to be coping relatively well on the second day. The challenges she faces are handled with a bit more effort than usual, perhaps due to her being slightly younger mentally and physically, but overall, Sapphire is managing to keep Lily looked after and the house in order. There are small moments where her youthful impulsiveness or lack of focus may show, but nothing too significant. However, as the day comes to a close, it's time to see if Lily makes another attempt with her mysterious powers to siphon more of Sapphire's age. Let's find out how successful she is this time. Please roll the d20 for Lily's power attempt for the second day.

With a roll of 2, Lily's powers don't seem to be working well today. It appears that her attempt to siphon more age from Sapphire is largely unsuccessful. This could be due to Sapphire's innate resistance, perhaps a subconscious protective instinct, or maybe Lily's powers are unpredictable and not fully within her control. Sapphire retains her current age of 15, and her subconscious defensive mechanisms do their job for the day. As the second day winds down, she remains the same, apart from the slight age drop from the previous day. Let's find out how the third and final day goes for Sapphire's caretaking duties. Roll one last time for Sapphire's actions during the day, considering the same slight penalty as before for her regressed age.

Maintaining consistency from the second day, a roll of 12, accounting for the slight penalty due to her slight age regression, indicates that Sapphire is once again handling her responsibilities quite well. While there might be a hint of youthful exuberance or minor lapses in judgment compared to her original 16-year-old self, she is managing to care for Lily adequately and keeps the house in a reasonable state. As the sun begins to set on the third and final day of Sapphire's babysitting stint, curiosity lingers about whether Lily will make a last-ditch effort to tap into her mysterious powers. Let's find out if Lily is successful in her final attempt to siphon off any more of Sapphire's age. Please roll the d20 for the last time to determine the outcome of Lily's power attempt for the third day.

With a roll of 19, Lily's attempt is frighteningly successful on the third day. Her mysterious powers surge with unexpected intensity, and she manages to siphon a significant amount of age from Sapphire. Considering the high roll and the power of her success, let's determine that Lily siphons off four years from Sapphire. This dramatic change transforms Sapphire into an 11-year-old, both physically and mentally. At this age, her capacity to care for others and manage household tasks is surely compromised, and her behavior would now reflect the typical preadolescent child rather than a responsible teenager. Since Lily has grown past Sapphire in age, Sapphire no longer has caretaking duties. Meanwhile, Lily has likely aged herself up to a point where she is now in her late childhood or even early teen years, depending on how her powers exactly work. Since Sapphire can no longer effectively care for her, the dynamic in the household changes, and there might be new challenges for both of them to face. Now that Lily is older and Sapphire is much younger, the conclusion of this scenario depends on the new dynamic between them. Has Lily become the caretaker, or do they find themselves in a situation where they must explain this mysterious situation when Lily's mother returns? The storytelling possibilities are intriguing!