Anything You can Do I Can Do Better (swapping villains in scenarios)

So.  You've played through the Baron Blade scenarios a few times, and you think you know when to Teleport, when to Dodge, and when to Power Splice.  But what if it isn't Baron Blade trying to take over the power grid, but Tachyon?  Are her supersonic legs better at getting around the city than Baron's Teleporter?  What about Ambuscade's Cloak?

Who is your favorite substitute villian in a scenario?  Who would be broken, and who would make an interesting but balanced alternate?  I think Proletariat could be ridiculous in BB Scenario 2, if he were to start deploying turrets 3 or 4 at a time using Overwhelm.  Ambuscade might be broken in BB Scenario 1, with Cloaking and Feedback Plating.

Haven't tried substitutes yet.

I haven't even gotten through each scenario yet.

Proletariat in the Dawn scenarios would be neat.