This will be one of those agree to disagree things then because he has several times indicated a distinction in personality. I'm not saying it's a multiple personality thing, but he does act different when he is the demon king. He definitely doesn't wrestle different, but there is distinction.
Okay...so first things first...Finn needs to fully recover from his injury and work out
whatever "ring rust" he has...with that out of the way...
I really do hope the WWE take a chance and explore the Demon King persona...and
there are subtle ways to do it without truly slipping into "this is just silly" territory.
Idea:
After returning from his injury Finn begins to show strange behavior...perhaps he's
more openly aggressive towards the WWE staff and referees...perhaps he shows up
to do a backstage promo with half his face painted...and when questioned about it...
he doesn't remember the paint being applied. Perhaps a backstage altercation with
Gallows & Anderson...a slow build over time that chips away slowly at Finn.
Perhaps in a moment of clarity Finn is shown talking with Bayley...giving her advice
and tactics about her current feud/opponent. Finn explains that you can never show
weakness...not to your enemies, not to your allies...but most of all...not to yourself.
During what seems like a simple conversation it turns serious as Finn explains that
"he" blames him for being weak...that the body "he" shares with him is weak...frail...
fragile...and that "he" finally claimed a true crown only for Finn to give it up.
Bayley seems to understand but like everyone...she doesn't realize how deep Finn
was wounded by Rising and Falling so quickly...to have the dream come true...only
to fall into a nightmare...And internally the Demon King blames Finn for holding him
back and making him weak.
Because while the Demon King is part of Finn...the part that failed them is all Finn...
His mind did not break...his body broke...and even though the Demon King would
have kept fighting and ruling his kingdom (the WWE ring) he couldn't...because
the shell he resides in was cracked.
You see subconsciously Finn is willing to let his other side...the Demon King...take
control...because he knows the Demon King makes him better, makes him stronger...
makes him...more...and not only that...but Finn feels he owes the Demon King...
because the Demon King has given him so much...it has allowed him to live his
life doing what he truly loves...wrestling.
A triggering event would be needed...perhaps a Universal Title match...perhaps a
No.1 Contenders match...perhaps it could be something simple...something shown
in a backstage segment...but whatever it is...from that point on...the Demon King
is in control...and from that point on...allow Finn (as a performer) to truly explore
the character...turn it up 11 and run with it.
Make the character...the persona...more than just paint and crawling around on
the ground.
And the story you tell is...
The Rise and Dominance of the Demon King...
and then...
The Redemption and Acceptance of Finn Balor...