An ordinary day, an ordinary city, an ordinary supervillain plotting to tear holes in reality and unleash extradimensional monsters on Chicago...
Well. Not that ordinary.
"LOOK," says Mirror (the superhero currently bouncing around the oversized laboratory, light-armored costume still sizzling from where a death-ray beam just hit it) "I'm not saying you aren't going to unleash monsters on Chicago!" She propels herself off a shelf of tools, sending herself flying into one of the upper walls, reversing direction in midair when Doctor Dimensional's death ray beam drilled a hole in the wall) "I'm just saying you can't know they're actually extradimensional monsters!"
The good Doctor spun his death ray towards her. "Would I not have chosen a different name, if they were biologically created monsters? If they were robots? FOOL! I shall summon legions from BEYOND THE VERY STARS THEMSELVES!"
"I recognize the logic -" (zap!) "- trust me, I do! But - sorry for bringing this up - you are a tinker!"
"My genius is far greater than any normal man's!" (As some evidence behind this, Doctor Dimensional was inside his portal device's personal force-screen, which did not, as it happened, block his death-ray's shots)
"Exactly! You can do things normal scientists can't! But the thing is you're a full-scale reality-warper -"
(she bounced off a stack of equipment, sending it tumbling to the floor in shards, and the Doctor cursed)
"- like all tinkers. So we don't really know whether the alternate dimension existed before, or was created by your powers!"
"That you think I have the ability to create an alternate dimension purely through my own abilities? What foolishness!"
"Why not? The False Sage does."
"The False Sage is a man of GENIUS! Now, meddling fool, should I wrench the fabric of reality aside to unleash horrors beyond comprehension upon your world, you will SEE my greatness!"
"No, I won't! I'll just think you're a summoner! Look, I'm very sorry, but -"
"You WILL be sorry!" (Zap! Zap! Zap!)
"Look," (Dodge! Dodge! Dodge!) "You'll grant Voidwrath isn't a real alien, right? And the Empyrean Sage's minions? I really think the base rate of summoners is higher than the base rate of preexisting-alternate-dimension-accessors, and you aren't actually providing me with a way to distinguish, so the odds -"
"A true VISIONARY scientists LAUGHS at the odds!"
"Right, but an scientist calculates probabilities -" (She bounced off, and another death-ray blast seared a hole in the walls. The lights began to flicker.)
"- Such as the probability that I only need to keep bouncing around and letting you shoot for long enough, and between the two of us we'll take out your laboratory's power." The lights went out. "Now, I already had the you-must-learn-to-fight-in-total-darkness adventure. Blacksand, you know. What about you, doc? How do you feel about fighting in total darkness?" Her voice seemed to come from all around him.
"I feel that my gateway device has its own separate power source. BEHOLD THE HORRORS I CAN UNLEASH!"
And he threw the switch.