Had a session of Feng Shui tonight with a fight that went twice as long as I thought it was going to. It was one of those situations where each villain had a specific weakness that corresponded to a different hero, and the PCs noticed, but chose to fight different foes anyway, at least until the fight was nearly over.
One NPC had a Defense of 12 vs Ranged Attacks, but a really strong Defense 15 vs Melee. So the team's biggest Melee hitter went after him, and kept missing by 1 or 2 every attack, while the team's shooters chose other targets entirely. And since he kept just barely missing, no one came to his rescue, as the shooty characters all assumed he'd wrap it up with one lucky roll.
Meanwhile, one of the other PCs has a special power that lets them change their damage to be +1 higher than the damage rating of the foe they are attacking. He ended up dueling with the lowest damage rated foe all fight long, so they just nibbled each other towards death very slowly.
It was interesting, in that everyone was having fun and things were lively, but like I said the fight was at least 50% more challenging than intended, and ran nearly double the length I expected it to. If 2 or 3 of the PCs had traded targets, it would have been a much shorter fight.
The timely application of the "Flying Guillotines" Schtick by the main villain meant everyone was excited and involved at all times, even if a lot of attacks failed to hit big. There's something pretty engaging about an enemy that can zap you with a weapon that's an all-but-guaranteed kill unless a nearby hero helps you escape from it. A lot of "somebody help!" and "I'll save you!" moments, so it kept things tense. At one point a PC with a Flying Guillotine wrapped around their neck had to jump out a window to reach to the only person that could possibly save them before the scissoring blades would have decapitated them. If that dynamic hadn't been in play, it might have been a boring match up (and I might have had to have the other NPCs try swapping targets to pick up the pace).