What exactly do you mean when you say agriculture
I mean small-scale, labor intensive farming, akin to the agricultural methods of the late stone age, or the early bronze age.
Mantids are carnivores. I'd expect them to become nomadic herders, not farmers
Any mutation. It depends on the type of jod. Some jod might even do both. The mutation might be good in one situation and bad in another. The jod might also just go crazy and give you cancer cells. I'm also well aware of how energy intensive that would be but if it happened as the GM says then they must've done something. I'd love it though if the only reason the mantids grow crops is for beer though.
Right, I forgot while I was writing the Turn Two Update, thank you for reminding me. I'll Edit the Update to reflect their diet better. Although, I could easily see a few permanent settlements surviving on Alcoholic Trade, Hunting and Fishing.
Any mutation. It depends on the type of job. Some job might even do both. The mutation might be good in one situation and bad in another. The job might also just go crazy and give you cancer cells.
So if I made a harpoon out of the right type of Jod, and stabbed it into the Herald, it'd turn into a blob of cancer? Neato.
EDIT2: Would it be fine if I made the Chain of Cuttle out of Cancer Jod?
Unless you enchanted the Chain with at least One Minor Act, it would be as fragile as ordinary Jod, and easily broken by a Titan as Powerful as The Herald. If it was enchanted with a Minor Act, The Herald could also attempt to destroy it, and, as the Herald was created with One Major Act, the Herald would receive a bonus to it's Attack roll against the weaker Artifact. If the Chain of Jod wasn't destroyed, and gave The Herald Cancer, it could attempt to Heal itself or resist the Disease, requiring another roll. Or, Envaruk could Heal it with One Minor Act, or destroy the Artifact. If the Chain was enchanted with One Major Act, the same as the above would be true, except the rolls would be much less balanced in The Herald's Favor, as neither would have an advantage in Power. You could do many things besides creating a Chain of Jod to defeat The Herald, you could create another Titan to Fight The Herald, you could give the Cuttles the ability to survive on Land, you could create a Mortal Champion to oppose him, and so on and so on. Being a Divine, there are many, many possibilities.
I'm sorry if I hadn't mentioned this earlier, but I've been rolling a 1d20 to measure the success of each Living Creation, putting in modifiers based on Technologies, (If it's a Mortal Race) and the amount of Power that went into it's Creation. During conflicts, I roll a 1d20 for both parties involved, and the degree of the success of the Victor depends on how much higher they rolled than the Loser. For Example, with the Cuttles and The Herald, I rolled a 1d20 for both, since both had One Major Act invested into them, the rolls were even. The Cuttles rolled a 3, as opposed to The Herald rolling a 16, if the Cuttles had rolled a 16, as opposed to The Herald rolling a 3, The Herald would be severely wounded, and/or starving at the bottom of the Ocean right now, and the Cuttles likely would've flourished. As a general rule, I as a God-game GM, don't drive Mortal Races extinct unless it benefits the Plot, as it reduces the versatility of the Setting as a whole, but if the Cuttles had rolled a 1, as opposed to The Herald rolling a 19, or 20, the Cuttles would've gone extinct.
I hope that cleared everything up. The Turn Three Update will take place shortly.