The possession of knowledge does not kill the sense of wonder and mystery.
There is always more mystery.
Rin can sense auras and perhaps, auras, is not an accurate term but it's the closest he's ever come to describing it even though the word doesn't feel quite right. The half demon can't see them there are no colors although sometime he thinks that if he manages to still himself long enough he swears he can hear what their souls are singing.
The first time it happens is on accident. He's in the room he and Yukio share trying to drift off to sleep when he notices wind. Suddenly the room feels itchy switching from burning hot to freezing cold. Rin ignores it at first. Temperature has never truly bothered him before. It gets worse however, the more he relaxes the more he knows.
Steady, silent beats of the classical music Yukio is so fond of. The wind swirls into a hurricane, sweeping up all that is in it's path in a constant torrent of banging metal and herbs breaking the clouds while heavy rainfall and gunfire echoes in the background and empty shells clang on the cemented ground.
A chill sweeps in the background wind still howling in constant fury as snow blankets the ground, the mechanical sounds of footsteps cry out as electricity shoots through thin wires and gears shows turn in a well oiled machine, alive yet not alive. Too loud. Too much noise.
Yukio sleeps straight through Rin's inner turmoil. Rin ends up crawling out of his bed.
Kuro who was sleeping on his bed and Ukobach who had taken a liking to doing the same looked at him curiously.
'Rin?' The cat sith yawned, 'What's wrong?'
'Nothing Kuro.' Rin responded gently stroking his familiar's furred head. Demon telepathy was very convenient for times like these. (Despite what everyone who knew him though he could be quiet when he wanted to.)
Rin quietly snuck out of the room and ended up falling asleep on Mephisto's purple coach in his office as it was the quietest place he could think of. The elder demon had walked into his office Amaimon in his animal form on his shoulder and sitting down.
It takes a few moments of Amaimon persistently nibbling on his hair for the elder demon to look up and spot their younger sibling crashed upon his couch. Curious Mephisto stands up looming over Rin curiously.
A single blank red rimmed blue eye slides open to gaze at him and for a moment Mephisto fears that its his father's eyes he's looking in and evidently Amaimon felt the same judging by the way his tiny paws are digging into the fabric of his jacket.
Those fears are quickly quelled however as Rin stares blankly at Amaimon and in those few seconds he knows.
Knows that he isn't staring at a normal hamster although the green color really should have given that away but Mephisto could have just been being weird.
Instead all he can sense is the beings grown from earth, vines, herbs and poisons, tightly controlled tension ready to break dense terrain at a moment's notice. A wild roar from the king of beasts against wild uncontrolled against the untamed, rampant whirlwind and nature's untamed fury.
Rin's gaze is intensely focused against Amaimon's small form, a second passess as the youngest of the three gives a lazy blink before snatching the earth king from his resting place holding the demon in the palm of his hand.
After a moment's silence Rin blinks again a happy spark lighting up his eye as he declares, "I'm gonna call you mini-Mon."
Mephisto burst into mad cackles a crescent shaped grin making itself known as he chuckles at the newly dubbed 'mini-Mon Demon Hamster King of Earth'.
Amaimon proceeds to bite Rin's thumb.
Still chuckling Mephisto sits down, "So what has caused you to grace me with your presence so early?"
Rin shrugs carelessly, "I needed somewhere quiet."
Both Amaimon and Mephisto can tell there is something more to it but they decide to drop the subject, for now. Rin ends up staying there the rest of the day, skipping school with the man who is supposed to be his principal as he talks to his more demonic brothers.
Yukio eventually notices that Rin has been avoiding dozing off whenever the younger twin is around. The worried look continues until the older starts faking sleep so the other won't age thirty years over night.
During classes Rin focuses on Shima's aura which is the calming sound of rushing water and gentle rainfall, and a steady drumbeat along with the sensation of watching all of it from inside warm blankets next to crackling bonfire while scenting the smoked wood.
It suited the pink haired exorcist rather well considering his laid back attitude. The son of Satan would not deny he had scared Shima half to death when he had decided to use the other male's lap as a pillow.
Although that could have been because Bon had tried to scream at him to stop sleeping he had grabbed the aria in training's collar before releasing a low growl that promised an excruciating death as he threatened to 'break every bone in your body, slowly skin you alive, before harvesting the meat and feeding it to the closest demon I can find.'
Yukio had taken to explaining the lie Rin had fed him about being up late reading manga. Either way they had left him alone for the next few hours so he couldn't exactly complain.
Bon's wasn't bad even if Rin thinks that it doesn't suit him; It's a plain field with a single flat stationed in the middle of long tall grass that swishes with the soft gentle breeze that occasionally turns into a gale wind.
Rin didn't like Shiemi's simply for the fact it was to hesitant and gentle, frost formed on the early morning windows, soft grass and numerous flowers and herbs that could all too easily collapse if not taken care of properly.
Konekomaru was hesitant but made of more steady material than what many others gave him credit for. Flexible metal plating but unyielding along with snowfall and playful bouncing kitten.
Foxes came as no surprise with Izumo's aura but the newly sprouted plants and scent of spring did along with large winding trees with vibrant green leaves moving with the air.
Shura's absolutely terrified him since it was a predatory snake in it's den sizing up it's prey trying to decided how much it could eat before the world erupted into a blazing inferno.
When he woke up Shima was shivering from the cold and the half demon felt bad enough that he cooked all of the monk's favorites for the next week.
Oddly enough Shima never minded lending his lap after that. Rin decides that although Mephisto's aura is his favorite, Shima's is a close second while Amaimon was an even closer third.
It takes a few more more sleepless nights and visits for Rin to admit what was going on. Mephisto and Amaimon listen attentively.
Mephisto takes a sip of his tea as he sits in his cushioned office chair, Amaimon still in animal form nibbles on one of Rin's homemade cookies, finally he asks "What does my 'aura' feel like to you?"
Rin hums thoughtfully "You're like…" For a minute he struggles with his words before deciding to let them flow naturally, "The sun and moon slowly elapsing across the sky, the days wear, and the slow burning of a fierce, ardent star begins to dim, fluttering of shadowed wings just beyond a slow ticking of an infinite pendulum of seconds swings, frantic, untamable, and mischievous, darkness hides glittering watchful eyes while you stalk patiently watching each step, breath, and thought with lazy indulgence and mocking, vicious amusement until you devour you victim." The half demon breaks out of whatever trance he had been in unsure if he should continue.
Mephisto stared at Rin for a long moment, "It seems," The Demon King of Time ponders, "That you are capable of summoning me now."
"That–" Mephisto gives out a half amused half bewildered cackle, "–was the chant that, if you had finished, would have summoned me."
After a few more moments of completive silence only broken from mini-Mon's constant nibbling on his cookie.
"Fuck." Rin breathes because even he knows the importance of being able to summon a Demon King.
They decide to drop the subject. It isn't mentioned again.
Until it is.
A profound sense of the universe.