Delenn: What is it?
Ivanova: When Marcus and I were out looking for the first ones, we came across an Vorlon fleet hiding in hyperspace.
Marcus: Not dozens, not hundreds, but thousands of ships.
[Lorien leans forward, taking an interest]
A couple of them were three to four miles across. We tried to track them but we lost them somewhere around Sector 70.
Delenn: There's a Shadow base not far from there.
Ivanova: Exactly, so as soon as we got back I had C&C monitor that area for any transmissions, anything unusual. The Shadow base was located on a planet called Arcada Seven. It's not there any more.
Lennier: The base?
Lyta: No, the planet.
[Lorien leans forward even more, a look of worry crosses his face]
They destroyed,… they destroyed and entire planet.
Franklin: Lyta, there are over four million people on Arcada Seven,… you can't be serious.
So, the Vorlon ships are true planet-destroying weapons.
Also, the essay made reference to the Shadow Planet Killer stating that:
Yet, how would this cloud be controlled if it wasn't made of nano-bots? It has to be composed of diffused particles, a gas would spread out until it was equalized with ambient air pressure, which would be 1E-8 Pascals in LEO over a planet like Earth and several orders of magnitude lower in interplanetary space. The particles move along with the main node and can change shape. There must be some mechanism to control these diffuse particles.The Shadow planet-killer is a giant spaceborn MLRS (multiple-launch rocket system) concealed within an energy-draining cloud. Some Babylon 5 fans claim that this cloud is composed of nano-bots, but that seems absurd. Nano-scale constructs (either mechanical or biological) have an extremely low "thermal capacitance", which is an engineering short-hand way of saying that their ratio of mass to surface area is extremely low, so they heat up very quickly in the presence of radiation (yes, size matters). In other words, thermal radiation which would be harmless to a conventional vehicle or even human skin would rapidly heat nanobots to the point of destruction (this is why microbial life forms must encase themselves in spores or they won't even survive sunlight). The radiative output of a single megaton-class nuclear weapon would destroy all of the nanobots in a volume of space encompassing at least many tens of thousands of cubic kilometres. Only a lunatic or a fool would build a superweapon out of a cloud of nanobots.
Also,
The questioning of Shadow tech because of its vulerability to telepaths is as errorous as saying that the US military 'have been aware of a computer virus vulnerability in their basic computer system design for over thirty years (computer viruses can destroy programs, thus stopping computers cold) yet they have done nothing whatsoever to remedy this crippling design defect." The fact is, Shadow warships use telepaths to operate their ships much like we use computers today. The vulnerability is based on a need for telepaths like we are vulnerable to certain computer programs because we need computer programs for running the computers that controls our commerce, transportation, military, etc (hence, the fear of the end of civilization due to the Y2K computer glitch). Also, warfare is a constant cat-and-mouse game of measures, countermeasures, and measures to counter the countermeasures and so forth. Example is air combat in WWII. In order to stop bombing raids, the Germans set up anti-aircraft guns around their bases. Allies bombers would fly either at night or through cloud cover to avoid being seen. In turn, the Germans built radar stations to track Allied bombers. The Allies then used strips of aluminum foil cutted to one-quarter of the wavelength of German radar called chaff as a sort of smokescreen to confuse German radar. The Germans then started experimenting with radar signals at higher frequencies, only to have the Allies use chaffs cut at various sizes for different frequencies. Remember, all of the telepaths in each race were created by the Vorlons. I can only image the Shadows set up countermeasures to only allow their telepaths to control their ships only to have the Vorlons find a way around it. Military technology is in a constant state of flux not unlike a game of chest. It would foolish to assume the Shadows didn't try to make countermeasures to keep telepaths from disrupting a ship designed to be operated by a telepath.The intelligence of the Shadows is questionable for other reasons as well; for example, they have been aware of a telepath vulnerability in their basic warship design for more than a thousand years (telepaths can jam their warships, thus stopping them cold), yet they have done nothing whatsoever to remedy this crippling design defect.