A devil heart was a special type of parasite used by demons in the past, it fed on the negative emotions of its host, slowly corrupting the body and reforging it to accommodate the demon who planted it.
But there were certain conditions required to implant it into a host.
The demon itself had to come in contact with the host, or another vessel housing a devil's heart.
Furthermore it required a blood exchange between the host and the demon or its vessel.
That said, it wasn't a common process that could happen without one's notice, considering the amount of physical contact involved, it was almost impossible to be carried out without being discovered.
That also begged the question, how did a demon evade the notice of the Astavore's eldest daughter.
From what Lily could tell, Leona was if anything, quick witted and observant, very observant.
She couldn't imagine Leona agreeing to implant a demon heart on herself, the Astavore's loathed demons.
They were practically a house of demon hunters as well.
So that left only a few options she'd rather not think about.
Lily fiddled around with a few strands of her hair.
Her eyes narrowed in concentration but after a few minutes she let out a huff.
"What a load of unnecessary shit, it works for us no? Besides there's no way a demon could've bypassed the barrier between the mortal realm and the demon realm."
She stared at Liliana thoughtfully.
"I… haven't sensed any demons in the household lately, perhaps she got it at the academy?"
Liliana slowly stood up from her throne, her black dress rippled like liquids before transforming into something which seemed like a summer gown.
As she moved, black chains forged out of a strange material burst forth from the obsidian mountains.
They wrapped around Liliana's form, holding her in place and tightening with each step she took towards Lily.
Lily stared at the chains.
"They've gotten weaker."
Liliana smiled.
"That they have, my adorable sister… but let's focus on the matter at hand."
"Why do you even care, it's not like it goes against what mother wants right?" Lily inquired.
Lily wasn't wrong, she was a demon not a human, she had no reason to care.
There weren't any attachments she had to Leona. If a demon wanted to take over her body then she couldn't be bothered to care.
In all honesty, the most logical thing to do as a demon was to help in speeding up the process or at least make sure no one could interfere.
Even if the demon had a separate goal, once they got a hold on one of the Astavore's then the barrier interfering between the demon realm and the mortal realm would be removed.
Liliana hummed softly, her tone as serene as a siren's.
"Why do I care? Hmmm I wonder…"
She exhaled, her gaze tracing the faint stars above.
"Dear sister, have you ever heard of a devil bond?"
"A devil bond?" Lily repeated slowly, the words came out with uncertainty.
"You could say it's a demon's version of what humans call soulmate, our fates are linked together with that human Azazel's."
"What do you mean?"
"You feel it too, no? That strange pull towards him, the unnatural attraction you have for him…" Liliana's smile grew a bit, her lips parted, just enough to utter a few words.
"Well don't jump into conclusions yet though, it's not like you love him or anything, it's his essence. When a succubus meets a man who's perfectly compatible with them, their essence becomes a drug we can't resist, an addictive one which we can't seem to live without."
She shrugged, an action which looked quite comical considering she was bounded in chains.
"What I'm saying is, you won't notice it now but eventually the effects of taking a portion of his essence will show up, and if he's not alive by then well, you'll be starved till you find another person whose compability matches yours and if you don't? Well you'll die or rather we will die."
Lily scowled.
"You're not making sense Liliana, what does Leona's devil heart have to do with Azazel?"
"Oh but it does Lily, everything has to do with him." Liliana remarked with a chuckle, "The devil's heart can't fully manifest if the catalyst is still alive, Leona has to kill him in order for it to bloom and believe me today won't be the last time she subconsciously tries to murder him."
"So… what should I do? Kill her? In the first place it depends on the demon who owns the devil heart."
Liliana merely stared at Lily as though she could see something no one could, her lips curled into a thin smile.
"Well Lily dear, I hate to break it to you but that demon is far too big a deal for you to kill it the way you are now, the owner of the devil's heart is Asmodeus the demon prince of lust and desire, and being a succubus yourself I'd say your chances of killing him is none."
Lily stared at the crimson lake far too long than she cared to admit, her brows were drawn in concentration, like she was calculating rather than thinking.
After a few seconds she returned her gaze, allowing it to linger on Liliana.
Eventually she spoke, her tone however had adopted a cold pitch.
"Can you kill him?" She asked.
Liliana's smile faltered, her expression became serious, something very rare as she'd always had a sly smile or her face.
She stared at Lily, frowning as she tried to assess whether her human self was playing a joke on her.
When she noticed how serious Lily was, she answered.
"Even with all the sins unlocked, I'd have a hard time dealing with him."
As she spoke, the chains pulsed like beating hearts.
Yes, each of those chains were sins.
Lily or rather Liliana had a very special ability.
She could utilize any sin she wished to, it was the same as trespassing into the domains of the demon princes.
She could use their respective abilities, however her restriction wasn't so convenient.
She couldn't use it without a partner, in order to use her ability, she needed to feed off someone's sin.
Lily could only release one of the chains because Liliana envied her.
They were the same but Lily was free, unlike her who was held down by the very thing meant to give her strength.
She loved Lily as one would a younger sister, but she was undoubtedly jealous of the freedom Lily had.
And because of that, Lily could remove the restriction of envy placed on her.
Liliana's lips curled into a knowing smile as she asked.
"~My, My… don't tell me sister, you're thinking of releasing the seal?"
She'd said it as a joke but Lily was dead serious.
"If doing that would give me the time and strength to kill asmodeus then I will."
Lily's expression morphed into a scowl.
"How dare that demon place his sights on my food, Azazel is mine and mine alone, I've been starving for so long and now that I've found something to snack on, Asmodeus wants to take it away? that's unforgivable."
Liliana blinked at Lily's outburst, then burst into a fit of laughter.
The sound was melodious yet terrifying at the same time, causing the crimson river to tremble.
"Now isn't this pleasant, after all this time, I'll get to have a taste of our little prey…. Ah I can't wait~."