Yuki couldn't help the prince, at her state, using her trembling and unstable force to help him was suicidal for both of them, it would harm him rather than recovering...
But when she felt Aki use his 'magic' consciously, she could finally see a path.
Before helping Aki, she had also sent her force to stabilise the prince, she had wanted to throw all her cards and get done with the two of them at once, if possible, at least, she wanted to create a barrier around his core, but the result was disappointing.
The crown prince, even in this state, didn't let her in, she couldn't help him if he didn't allow her to 'invade' his inner core, but she could still understand him, she was similar to him, she never let anyone 'invade' her unconscious, she never allowed that too!
At that moment, she had decided to help Aki first and after she was done, she could send Aki to get someone for help... but in the end, the condition became a bit worse than earlier; her body wasn't responding to her at all and he reckless currents from the prince were enough to put Aki in his place, he was unable to move.
She had already given up hope and was going to become a bit reckless by forcing him to accept her, the end result was given, the prince would break and she will probably offend the imperial crown, she will also break her own core in the path, but Aki will be saved... it was the worse choice, but she had promised to be a bit selfish in this life, if push came to shove, she didn't mind sacrificing both their lives to save Aki, he was his priority!
But just then, Aki true to his first name, enveloped her whole figure in the gentle light of the moon, he was like the Goddess of Moon descending on "Erlen" itself...
She saw a glimmer of hope, in her literally dark world.
It will be pushing Aki to the limit, but she will back him up and the best outcome was, all three of them will get out of this alive.
She saw the prince twitching like a dying fish on the floor, his physical strength wasn't enough to withstand his own powers, the person who was suffering the most at the moment was him, in compared to the physical pain she was forced with, his mental, physical and soul force as a whole was going against him, well, the only good thing was that, if he crossed this phase, he will see a tremendous rise in his core capacity, but that was possible only when they come out of this alive and well!
She didn't have enough time to explain everything.
She directly put a strong barrier using all her force, leaving just a little to support the kid and turned to Aki, at this moment, she wants to cough out blood, literally, more than anything, but she gulped everything down and said in a whisper, well, she didn't have enough energy to talk any better...
"A..ki... I ..need.. your help..", her breathing was heavy and everything came out in hoarse whispers followed by deep panting sounds, she had reached her limit.
Aki who had been depressed, but had instinctively done something to help the two of them was feeling a bit tired himself, him using his powers put on a mental strain on him... nothing came for free, it was the world's law.
Still, he will do anything for his Onee-chan, he wanted to be useful to her!
Aki wiped his tears and spoke seriously, "I'll do it."
Yuki tried to give him a smile, but it looked miserable...
Still, she won't mope around, she brought Aki closer to the prince, both her and Aki's magic was covering them and they didn't feel much repulsion, but the hard thing started after this.
Yuki put Aki's hand over the prince's stomach, he had a violent reaction, but it subsided the next moment, Yuki's eyes shone... she was correct, he was instinctively allowing Aki to approach him... it was not a situation to joke, but she would have liked to say that, 'he had fallen too hard and too fast'
Anyway, the core was closer to the heart, it was the first time for Aki and her, she wouldn't want to directly push him there.
She spoke to Aki, "Aki close your eyes and imagine a full moon near your heart...", her voice was still strenuous, but she didn't want to falter here.
Aki followed the principle of 'Onee-chan was always correct' and so, he didn't ask anything and tried imagining it...
It wasn't hard for him, because he had been feeling a deep warmth close to his heart for quite a while now...
It was like he was standing inside a dark space, but above him was a huge white bulb sort of thing, ' is this the moon..?', he wondered.
Somehow, he knew that the warm light inside was his own.. as for the blinding white light covering it like a dome... he could feel the warmth of his Onee-chan...
He suddenly felt her presence beside him, though he couldn't see himself, let alone any other thing, he felt that his Onee-chan was closer, he relaxed a lot more and finally saw that, a trail of white light was coming out of the centre of the HUGE moon and went to a place nearby... she felt that the end of this was connected to his Onee-chan.
As if to affirm it, he heard her voice, " Aki can you feel it...?"