Siege Weapons for Ogre Mages

[Tvtyrant]

I'm currently working on a campaign where a warlord has a prophetic memory of the old Ogre Mage Empire and reunites the Ogres with hopes of reconstituting it. As part of this effort he loots the abandoned capital and gathers a number of magical siege weapons to use in his invasion.

For context on why the Empire fell, it had enslaved a large part of the continent and was dealing with a slave revolt during a war of succession. One of the claimants made a deal with a rakshasa lord to destroy his enemies, who twisted the terms to stop the birth of ogre mages so all successive generations were born as ogres.

So far I have a cannon that magically generates 5 swarms of wasps in a blast area on target and a cannon that looks like a huge wand that casts prismatic spray in a 1000ft line.

Any ideas on additional wonder weapons the Ogres could have dug up?

[Dienekes]

I like making my ogre mages kind of dark, brutal, and horrifying.

I’d give them something like a magic bell that when wrung everyone in the city they’re besieging must make a will saving throw or have their mind corrupted in some way. If I wanted to play up the enslavement thing it’d be to have everyone charmed to be their ally. If I wanted to play up the horror of the ogre mages I’d have it instead turn the inhabitants into savage cannibals.

Either way, have it only last a couple hours with those effected remember exactly what they did and how much they enjoyed doing it. So even the survivors have their minds broken by guilt and disgust for when the ogre again control.

[LibraryOgre]

How about one that transmutes large amounts of stone to flesh or mud? Either one would destroy a fortification, with the flesh one being a bit creepier (and feeding your army of carnivores).

Earthquake hammers? Massive hammers that direct an earthquake at a wall?

A rat or slime trebuchet? Flings its missile high into the air, where it becomes hordes of rats or a rain of some kind of slime monster?

[Tvtyrant]

Cannibal rage bell confirmed, with it effecting the Ogre's slave army as well because they have no idea how these work.

I love the slime idea, I think I'm going to have it be Transmute Rock to Slime and have the fortress slowly turn into flesh eating slimes. That one is a big mirror that turns rocks reflected by it into slimes. Slaves are fed into the back of the mirror to power it.

Thank you for the suggestions! I'm still open to more if anyone has ideas they want to float.

[Mr Adventurer]

Reverse catapult. Target a 20' radius area within 1000' feet. Everything in that area is violently snatched into the sky - make an Intelligence (siege weaponry) check against DC15. You have disadvantage on that check if the target area is more than 500 feet away. On a success, you violently move everything in the target area up to 1000 feet in any direction. If you move them to a new place on the ground, they take damage as though they had fallen 10 feet for every 100 feet you moved them. Creatures land prone. If you move them to a place in the air, they fall if appropriate and take the normal falling damage.

Creatures that are only partially in the area may make a DC15 Dexterity saving throw to avoid the effect.

If you fail the Intelligence (siege weaponry) check, you move everything in the target area only 1 foot in the desired direction for every 100 feet you wanted to.

If you fail the check by 5 or more, you move everything the maximum distance, and everything moves toward the location of the catapult.