First, some questions!

"Um... Are you sure you're alright with this, Robin?" Chrom asked her. He then looked at her tail. "And... Can you get your legs back?"

"Of course, to both! I just need your permission for the latter! And they'll automatically revert to the tail and reconnect to the Lamp the moment said permission expires!" Robin gushed. Her newly submissive inclinations made her take so much pleasure in the notion that her very mobility was determined by her owner's whim.

"Right. You have blanket permission to have legs unless I say otherwise," Chrom replied, and Robin nodded, detaching her tail from the spout of the Lamp, then it split into two, the mist coalescing into legs. Bare legs briefly, but her leggings reformed after a moment too. Which was very deliberate, and made Chrom flush. "...is there a way to undo this?"

"Um, well, there are two easy ways to free a genie of my type," Robin replied, grimacing at the thought. "First, I fulfill my quota. The Lamp feeds on sexual energies, you see. Which are created by of course granting sexual desires. On average, per genie, it takes a few centuries, in which case, it will spit the genie out, returning them to human form, unaged from the moment they were transformed."

"...and the other way?" Lissa asked.

"My owner can wish for it... But then the Lamp will automatically claim them, or, if they offer someone else up, that person to be the genie. Once it has someone, it won't remain empty until satiated, then it returns to where it came from. Please do not do this. I have no desire to be released," Robin replied. "And before you ask, no, it's not the Lamp's influence talking. I'd try to get back in the moment I was released if you did so. Then of course, whoever took my place would want back in, which is a whole issue I'd rather we not start."

"...right," Frederick replied skeptically. "And just where did this Lamp come from?"

"...well... It came from an entirely different world, actually... You know legends of the Deep Realms?" Robin asked.

"...yeah?" Chrom asked.

"From beyond even that, and no, I'm not kidding... Side note, the timeline of this world is split into two, currently."

"The... What? Timeline?" Chrom questioned.