Welp, we heard vanessa, Guess we're giving DEI to Janna if we somehow croak.
You joke, but if Vanessa legitimately isn't interested, I'd be willing to consider it. Not right now, obviously, but between Goofy, Khan, Mirage, Russ, Technor, Lee, and Wile, I think we've got a solid enough foundation that Doof getting killed and continuing the Quest with his heirs and Heroes picking up the pieces is viable. Wasabi might be spooked into leaving, along with some of our lower Loyalty people, like LOVEMUFFIN who only follow along because Doof can browbeat the lesser evil scientists into it, but most of our Heroes would probably be more pissed off than scared. Janna, in particular, is as likely to react as if she were a cornered rat being poked with a stick as anything else, given that she already fled one home. Alan is something of a toss-up. On the one hand, this is probably the closest thing he's had to a safe place in years and Doof getting knocked off is something of a coin flip in terms of whether he doubles-down or flees.
It's one of the benefits of burning so many Diplo actions on recruitment, really. Killing Doof is likely to cripple our Learning, since the new King is unlikely to have anything close(Jumba is much more of a researcher and experimenter than any sort of leader, Ludivine literally has a Trait for how scatterbrained she is, and Wendy honestly doesn't seem like the sort to go for Kinghood, Lee might work, but he's a bit of a totalitarian utilitarian waiting to happen) but may well be of little overall consequence to the DEI faction. For all our comedic nature, we aren't Orks, and headcapping us is probably going to cause as much or less chaos as it did for Kronos. Now, if somebody called in a massive strike, say, Toffee personally assaulting our HQ and killing half our Heroes including Doof, that might be enough to wipe us out as a faction, somewhat dependent on the half in question. That's not likely to happen unless he's basically already taken over the country though. Shego is similar, though more because we'd have to really really piss her off for it to happen, Xanatos is unlikely to make such a direct move unless we do something really stupid like threaten his son, Bellweather doesn't seem to have the military for it, Yokai and the Zaibatsu have as many daggers pointed at each other as anyone else, Judge Doom might be willing to go for it, but only if he could figure out a way to keep it from being traced back to him, which would take something along the lines of ENCOM collaborating to erase evidence to make even remotely feasible. Speaking of which, ENCOM lacks the realspace assets for it, meaning such an attack would either have to be a digital assault such as screwing over our bank assets(which would have literally everyone screaming at them) or they'd have to overwhelm our digital defenses so completely that they could send in forces via the SHIVA(which we haven't set up yet) and none of the other Kings are especially interested in doing anything but tending to their domains, excepting Phobos, who is currently dueling Toffee for control of the multiverse, and DORIS, who has to be extremely careful not to set people off, what with being a mind control faction.
So yeah, if we assume someone could take out the King of any given faction, DEI is actually one of the ones most well-off in terms of getting back up after losing the current King.