We are going to have a lot of fireball (or plasma) cannons on our fortress. I just think we should have at least one chaos weapon as well and if we're just going to have one, it might as well be a really powerful one. Remember what happened to that shaman when our dragon breathed chaos on it? It killed the goblin and gave us an ally (albeit not an extremely useful one). Now imagine pouring huge amounts of chaos energy on an advancing enemy army, killing tons of them and giving us legions of mutated monsters as well. If we don't like what they turn into, just pour down some spores and turn them into fungus spawn.
Well, some issues...
1. Expense
2. Fallout
We have to live here. If we keep irradiating the land with Chaos, it'll be harder to do so. Even if we don't hit our village, how many traders would be willing to cross a band of Chaos-tainted land to reach us?
It's not actually fallout, this isn't a nuke.
Well duh. Fallout is just a nice metaphor for all the insanity Chaos does.
Also, since we already have a sort of firebolt salvo planned, I think it would be better to go with the Chaos. Alternatively, we could try to give it a few different firing elements, which would also strengthen the Chaos. Because what's more chaotic than several different elements at the same time?
Le sigh. How about we just make a cannon room which we can buff with life, chaos, and fire from us, and death, chaos, and snakes from Krait? Maybe even get some earth and creation in with it. Heck, let's find a Water god to infuse some into it to! But not now, not yet. For now, just get it in the air and maybe add some AA flamethrowers.
The problem with this is that our primary enemies are all the foot soldiers of gods of order, they will have put in place measures to ensure that they can't be royally screwed over by the directed energies of chaos, a weapon that instead utilises life or fire will be much more useful since it will completely bypass the one attribute that all ten of those gods have in common, where as a chaos cannon would be rendered useless against them because of those ten gods of order. All of whom just so happen to be orders of magnitude stronger than us.
Nine gods of order orders of magnitude stronger than us.
And yeah, flamethrowers. Consider a chaos cannon later, when we have more time, more allies*, and fewer of our enemies are Order gods.
*Including a Water God.