While he was deep down quite evil, I really enjoyed the character of Sakyo.
He was basically the most rich and corrupt man in the world when it came to demons and money.
Shizuru falls for him, though I don’t really understand why.
Even his rich friends turned on him when they found out his true goal.
Which was a permanent tunnel to Demon World. Which theoretically would have brought the end of the world.
He bets his life on Toguro’s victory.
And when he loses the bet, Koenma tries to let him walk away with his life.
But he decides to take himself out along with his research. Got to respect his commitment to his bets.