factorio mod that just adds atomic artillery and shells for it
has a much longer cooldown between firing specifically so it doesnt target nests that are already going to be hit by one of its blasts
also has a farther out minimum range and maybe just enough added intelligence to not target close to friendly buildings and vehicles
maybe an additional shell variant called like 'fireball' or something that doesnt do quite as much direct damage but ignites everything in its blast radius for if you want to tank your framerate and commit war crimes against the biters
making it requires processing out phosphorus from stone and then making that into white phosphorus
