... You do realize that Unknown can, and has in the past, made use of the plot threads left behind by his opponent. This is, frankly, going to come down to a matter of theme. Unknown generally has an overall comical feel to his, but this has been slightly weakened after his last fight, where he jumped straight to the bloodshed likely in response to critiques about the Vampire fight. He's got to balance the two, otherwise this will be a critical flaw.
However blacklillian generally has a gritty and dark feel to hers, even when the laughs are apparent. This is usually consistent too, but the main flaw of theirs always seems to come down to the battle not really being focused on the actual battle. Although for some reason this never really counts against them. Balance is going to be key here for them too, because there are a lot of potential plot threads to be used.
A tricky fight overall. However suppressing my bias is hard when I really don't care much for the Professor duo...