TL;DR at the end.
So I have gone into a couple 160 missions with the exploding deathbomb modifier recently to see how much damage the exploding deathbombs modifier does.
There is definitely some inconsistency with the damage but there were one number I saw repeated the majority of the time.
This experiment was done in a 160 mission, nature storm, and I am Paleo Luna. My method is that I would make T3 brick and metal floors and then lure huskies onto it one by one and kill them.
For T3 metal (which has 9065 HP) I consistently saw that killing one husky on it would lower the HP to 7991 (for a difference of 1074). This was true for whether the husky was a physical or nature husky. And it was the same for whether the husky spawned one or two detahbombs.
I also saw a husky take T3 metal down from 9065 to 7665 and one time I saw a deathbomb take it down to 7454 (maybe I missed something else happening in that instance like a husk hitting the floor). I couldn’t really see a reason as to why sometimes the damage would deviate from the normal amount of damage. At first I thought it was because it was a nature husky and so it was doing extra damage on metal, but then I saw it repeated by a physical husky.
And then one time I saw metal drop from 7991 to 6592 from a physical husky and then drop from that to 5190 from another physical husky (so a 1400 HP drop each time).
For T3 brick (6860 HP) the number I saw the HP drop too most often was 5786 (which, like deathbombs on metal, is 1074 damage). This was true whether it was a nature husky or physical husky, and whether there was one or two deathbombs. But, like metal, I occasionally saw the HP drop to something else (like 5460 which is a 1400 HP drop).
Maybe deathbombs have a small chance to crit and when they do it is 1400 damage? 🤷♂️
So I think a piece of T3 metal can take about 8 or 9 huskies exploding on it before it is destroyed, unless you get some of the other random damage numbers then it could drop to maybe 6-7 huskies.
This seems to jive with what I see in missions. Over the past week I have done several 160 missions solo as Paleo Luna with the deathbomb modifier (won almost all of them) and usually I don’t see many structures getting destroyed. Though it does, of course, depend on how many huskies spawn. In one mission I had a lot spawn and in another mission I had hardly any spawn, so it varies a lot.
Also, I noticed that sometimes the damage of the deathbombs would also happen on adjacent tiles. So if I had made a 2×2 of floor tiles and a deathbomb would explode on one of them, it would sometimes damage some (or none) of the surrounding tiles.
Keep in mind I did this experiment with Paleo Luna, not a Constructor. Using a Constructor and placing a BASE gives you a lot of leeway (BASE gives you 60 armor which is 37.50% damage resistance). And using someone like BASE Kyle as your Commander not only gives you that armor but also increases building health by 84%.
That is who I usually run in 160 missions with deathbombs … the holy trinity of BASE Kyle in the lead, with PowerBASE and MegaBASE in support. And I never have a problem with propanes or deathbombs when using that loadout. Heck, I don’t seem to have any problem when using any random Constructor as my Commander (like Demo Penny) who doesn’t even buff structures like BASE Kyle does.
TL;DR Exploding deathbombs usually do about 1074 damage to T3 brick and metal (T3 metal has 9065 HP). There are some inconsistencies in how much damage deathbombs do, but that is the number I saw the majority of the time. Deathbombs do not seem to inherit the huskies element and there seems to be no difference in damage whether the husky spawns one or two deathbombs. The damage sometimes spreads to adjacent tiles. I only tested it in 160 missions so I don’t know if the damage changes in lower PL missions.