My thoughts:
* I think it's time to use our hero-summoning gadgets
* Blow the whole city up if we have to. I don't care about incidental casualties. All monsters lead by Gamington on mega-destructive-rampage-of-doom for a distraction. Give him a set of speakers capable of disintegrating city blocks and tell him to play Dance-Dance-Evil-Dance on buildings with monsters instead of on a footpad with his feet.
* I...am not certain that our personal attendance on the rescue mission is wise. This...is a trap. And we know it. Yes, I want to rescue Cerulean. In fact, at this point...honestly, Cerulean is more important to me than the long term survival of this forum game is. However, Cerulean was calling for her daddy. If we go barging in there, immediately after being seen with her in the hospital, after being seen with her by the other four members of her team...we'll be advertising to the world that we're the overlord, and not an adviser like everyone presently assumes.
Additionally, it's possible that somebody has already figured that out. Specifically, that heroic hero from the hospital mission. He vowed revenge on us, and he's probably not an idiot. He knows we're coming. And if so, and if this is a trap specifically tailored for us personally, then we don't want to be the one to trigger it. For example, if someone knew that Chemista was going to run a raid, they'd have flame prepared, even though flame might not affect another adviser (or us) as much. We don't want to barge into a trap specifically tailored for us. Let somebody else trigger it.
Therefore, I propose that we send Psysquid on the retrieval mission with specific instructions that his orders are to bring back Cerulean, collateral damage is not a concern, and he can release every inmate loose if it the resulting chaos will make it easier for him.
if he succeeds, great. If he fails, then we'll still have our major trump card: Overlord+Chemista, for a second attempt that will be made after the heroes are no longer on high alert, because they'll believe that they've already successfully thwarted the rescue attempt.