After a long and tedious battle, Dante stood victorius. He didn't kill the Master Librarian and instead, forced him to search for the demon that was last summoned and give him its book. Then, with a final strike of his sword, he banished the Master Librarian into the lowest pits of hell. Since demons couldn't be killed and only banished, this was the only thing he could do. By doing this, he also broke two more commandments but at this point, he simply didn't seem to care. After banishing him, he kneeled to Twilight and tried to wake her up.
"Twilight, wake up..." he uttered but she didn't move a muscle.
"Please, wake up..." Desperate and unsure on what to do, his conjured up the book containing the rules a demon should follow and looked for anything he could do to help her.
"It just isn't here!" he said as he was furiously turning the pages. "There's nothing about dark-leeched mortals!"
"Look... in the register..."
"Gee, thanks." He looked in the register for a few seconds and then it go to him. He dispelled at the book and looked at Twilight. "T-twilight?"
"You're okay!" he said happily and tried to help her get up. However, instead of letting him, Twilight places her hoove on his chest and said a faint "no".
"I... failed..." she uttered, once again starting to drift into unconsciousness.
"No, you didn't." he replied, keeping her head upright with one of his hooves. "I haven't seen anyone who could hold up for so long. You must have had a lot of happy memories." Happy indeed they were. One could even say that she had most happy memories of anyone in Ponyville, not counting Pinkie Pie.
"I... have... failed... Celestia..." she spoke in the sammer like she did before, keen on her failure to banish the demon. After all, it was all her fault and right now, it could be doing Celestia-knows-what.
"She tasked you with finding the demon?" he asked her. "Well, here it is." He showed her the book detailing the released demon's actions. Twilight didn't was unresponsive and instead, started fainting again.
"Are you a student of Celestia?" he asked her and she gave him a weak nod.
"What did she sent you to Ponyville for?" he asked again. "Why were you sent there?" Contrary to popular belief, even such creatures as demons and fiends were are informed of what's going on in the upper plane. Heaven doesn't want to share any information with them. To this date, no one knows why.
"To... supervise... the preparations... for the Summer... Sun Celebration..." she uttered. Sadly, none of them got an invitation to the event and even if they did, Celestia has forbidden every and all demons from entering the mortal plane. Poor fellas never had to put up with stuff like that during Discord. Those were the times...
"And what else?" asked Dante. Twilight was once again unresponsive and he didn't get an answer.
"Twilight, who am I?" he asked her in a saddened tone.
"Dante..." she uttered and her eyes closed again. Memory loss from dark-leeching is not a new or uncommon effect but to see it for himself. It was simply horrifying. She appeared to not remember anything related to friendship. He sighed, knowing that there's nothing he can do as memory loss from that spell is often pernament.
"History is not a thing unknown to us, demons, and a year ago, during the Summer Sun Celebration, you and a couple of other ponies stopped Nightmare Moon from making night eternal. The ponies who helped you were your friends. Friends." he lectured her in a sad tone. "Do you know what friends are?" he asked, but once again didn't get a reply.
"They're always there-" he said and hugged her. Then, he whispered "-for you." A single, gray teardrop dropped from his left eye on Twilight's horn. He then closed his eyes, knowing this was the last thing a demon could do to say goodbye. It was very uncommon but desperate times call for desperate actions.
Suddenly, a faint violet light appeared at the tip of her horn and her colors were slowly returning. Twilight didn't notice he was hugging her until she woke up again, cured of the librarian's spell and hugged him back.
"All the time?" she asked him. "Or just when they have free time?" Dante smiled, opened his eyes and let go of Twilight. And they say miracles only happen in the mortal plane. Reddish liars.
"Always." he said and helped her get up. "Always." Twilight smiled. She then looked around the library, curious what has happned to the Master Librarian.
"Is he... gone?" she asked, with a bit of worry in her voice.
"As gone as a demon can be." he replied. "In the deepest pit of hell." Twilight began taking books off the bookshelves and searched for the very demon she released. Like always, she couldn't find the book she was looking for. If only Spike was here with his book-finding skills.
"He gave me the book, if you're looking for it." uttered Dante and handed her the book. Twilight put all the books back into their place before turning her attention to the one he gave her. She opened the book and a horrified look was bestowed upon her face.
"Oh no..." she said as she was reading it and turning the pages. "This is bad."
"What did Cylyen do?" he asked.
"Arson, looting, robbery, property damage of forty houses and it keeps going up..." she said, worried. "But no one got hurt so far."
"What do you plan to do?" he asked her.
"Celestia told me of a procedure to rejuvenute a broken bond" she replied. "Have you heard of something like that?"
"Yes, I have." he said. "A demon can only be banished by it's summoner and technically, you're still the summoner , even if you broke the bond. Sure, you can try banishing without the bond, but it's take a lot longer, to say nothing of all the fireballs that would be hurled your way."
"Do you have any idea how to set up the bond again?" she asked. "Please..." She wasn't sure if using "please" still had an effect since they were friends at this point. Nevertheless, she was still a mortal and he still was a demon.
"I do, but it's very dangerous and may not even work." he said. "You see, since you accidentally set 'your' demon free, you can recall her by attempting to summon her again but if I know Cylyen, and I think I do, she'll resist your summons but inadvertly restore the binding."
"Well, I still remeber the spell but what's so dangerous about this?" she asked. "I mean, you would protect me, right?"
"If she fails to resist your summons, you'll see her in a form far stronger than the one roaming Equestria." he replied. "And even though I did manage to take on an archdemon, barons of hell are way out of my league. In other words, it's a risk." Twilight, though not used to taking risks, wanted to take this one since no other plan seemed to be logical. And so, she once again casted the same summoning spell but luckily, it failed but restored her binding. Out of nowhere, she felt a sudden burning sensation which, despite giving her a feeling that she was on fire, also gave her an almost unhealthy dose of joy from destruction.
"Heh, fire..." she said. She wasn't sure how to comprehend this but if barons felt like this all the time, maybe being one wasn't that bad.
"Twilight?" asked Dante. "You okay?" Twilight gave him a worried smile.
"Why do I feel an urge to set everything on fire?" she asked, smiling. "And why do I feel happy when I think about it?"
"Psychotic pyromania syndrome. Cylyen has it. Don't worry, it'll go away shortly" said Dante. "Fortunately, Hell is already on fire, so she won't burn anything once she gets back." Dante opened a portal and it looked exactly like the one he offered her earlier to give her a preemptive way back home.
"You coming?" she asked and Dante shook her head.
"Can't you make an exception?" she asked. "Just this one time"
"It doesn't matter who accompanies us," he said. "we're simply not allowed in there." Twilight saddened. It was sad to know that her new friend who helped her so much couldn't come with her.
"I... I don't want to say goodbye." she said, tears in her eyes. "Because 'goodbye' means gone forever..." Dante hugged her and smiled.
"And how about 'see you later' ?" he asked. Twilight giggled.
"I'm going to have to convince Celestia to let me visit you once in a while." she said, smiling. "You're not going anywhere, right?" This caused the demon to laugh, albeit in a normal manner, not in the one common with all demons.
"See you later, Twilight Sparkle." Twilight smiled and stepped into the portal.