does your muse talk to themselves when they’re alone? if so, how frequently and what about? if not, how else do they fill their alone time?

Kaiba used to talk to himself a lot when dealing with Gozaburo. Mostly as a way to remember what was being taught to him by his adopted father or by the teachers that were paid for. Sometimes, he will do it now whether in his office or in his lab or private study in the penthouse/mansion. Mostly to re-read over reports he is making, prepping for any broadcasts or press events, and the like.

He does keep music on in his office and he will lowly hum along to his modern scores or some songs if he is in a decent mood.

Kaiba has gotten better with how to fill in his "alone time" even though it had taken years of re-working himself. He tries not to immediately pick up his phone or tablet or laptop when given the chance or if he does, he tries to go to a different application or website and not immediately to his reports or to his blueprints.

HOW  LUCKY  WOULD  THAT  HAVE  BEEN     had  their  confines  not  kept  them  together  regardless.  It  leaves  a  puff  of  air  to  exit  his  nose,  dismissal  first  on  his  tongue.     " ... thrilling."    Second,  however,  is  the  belated  understanding  that  there  IS  a  target.  It  implores  Ryou  be  rid  of  the  book  in  his  grasp,  the  urge  to  skim  through  fictitious   horrors  now  sidelined  to  what  hither  draws  nigh.

He  finds  he  must  steer  his  head  and  shift  where  he  sits,     the  crawl  of  something  –     the  very  spelling  of  sinister  curling  beneath  the  folds  of  porcelain skin   –   begs  him  swallow  that  slump  in  his  throat.  Inaudibly,  with  caution,  as  if  he  could  ever  hide  his  inner  workings  from  his  vessel-bound  companion.    "Are  you  in  the  mood  to  tell  me  who  is?"     He  asks  it  without  pretense,  fingers  fiddling  with  whatever  may  trickle  of  snow-laced  hair  along  his  shoulder. If the ring sits heavier here under dimming light, let him enjoin it not prickle his sordid chest.

            𝐈𝐓'𝐒  𝐑𝐀𝐈𝐍𝐈𝐍𝐆  𝐖𝐇𝐄𝐍  𝐒𝐇𝐄  𝐋𝐄𝐀𝐕𝐄𝐒  𝐓𝐇𝐄  𝐒𝐓𝐔𝐃𝐈𝐎.  This  wouldn't  have  been  much  of  an  issue  for  Anzu,  except  they're  right  in  the  middle  of  Kaiba's  stupid  Battle  City  tournament  and  besides  all  of  that  mess,  she'd  been  late  for  dance  class.  Miss  Odori  had  been  less  than  understanding.  She'd  even  forgotten  an  umbrella.  She  was  supposed  to  meet  up  with  the  guys  afterwards  —  check  in  on  their  tournament  progress  —  but  now,  she'll  be  lucky  to  make  it  to  the  subway  station  before  looking  like  a  drowned  rat.

            Still,  Anzu's  no  quitter.  She  hauls  ass  anyway;  because  nothing  is  going  to  stop  her  from  showing  up  for  her  friends.  Not  rain,  not  thunder,  and  certainly  not  the  person  she  nearly  bowls  over  when  she  sharply  rounds  the  corner.

            Anzu  stumbles  back,  catching  herself  on  her  back  heel  before  she  can  send  them  both  flying  to  the  pavement.

Kaiba's eyes narrowed instantly as he looked at the other. His taller frame shifted in weight as he folded his arms across his chest, already annoyed and on guard with whatever Bakura wanted out of him this time around.

"I prefer my scent to be of a cologne that can be an everyday person's monthly salary and freshly printed Duel Monster cards or money. Just to correct your mindset."