"Quiet! Answer anything I ask truthfully and completely, nothing irrelevant. And quickly. What did you just do?"
"Don't do anything I don't tell you to do. Now answer me!"
Stops fighting Blossom, stops using magic, stops breathing. Now the being-on-fire-part is suddenly really painful, but he can't react.
"Blossom, don't let him inconvenience you."
Blossom spits out the vial at last.
"Put him out."
Alendi is no longer on fire.
Thorn walks over to Alendi.
"A mortal," he muses. "I suppose I could kill him."
"Hurt him first, Master," says Blossom, hissing.
Thorn runs his claws through her hair. "That goes without saying." He regards Alendi. And then, lightly, like it barely matters, to Alendi: "You may do exactly and only this: speak without omission, enforcement, trick, or other extraneous component a sincere and genuine reason I might not want to torture you to death for inconveniencing my Blossom."
Does the order to speak let him inhale? No, it doesn't. "I could get you a kingdom's worth of vassals," Alendi squeaks out.
And that I'd very much hope you don't do anything irresponsible with my kingdom because without me in charge the world might stop existing soon.
He's been visibly older ever since being told to "stop." He now looks the part of a healthy centuries-old human, which means he can barely stand let alone save the world centuries from now.
"I've been using magic to keep myself young and alive. When you told me to stop, I reverted to my chronological age."
"I don't know. There's nothing immediately killing me, but for all I know my body could decide to give out at any moment. No human has ever lived this long unassisted."
"Taking no opportunity to exceed the spirit of this order," Thorn says, "for the next five minutes, stop dying."
Blossom hisses.
"Be calm," Thorn tells her.
Alendi taps atium, and turns back to his usual age.
"Blossom would have me kill you just for your presumption," says Thorn. "And I mislike having someone around who calls my most precious consort his vassal. Tell me how you got here. To tell me what I want to know, you may breathe; if you form an intention to do anything extraneous, bite off your tongue and then calculate the cube root of every number between a trillion and ten trillion by brute force until further notice from me."
"I got here through a gate. It was made by a sorcerer I acquired, and it leads to one of your courts. From there, I captured Verve and made her take me here."
"Clock and Rainfall told me when she'd be in the garden alone, so I hid and took her by surprise."
"After I caught her I dragged her off and forced her to swallow some pewter dust from my world."