Finally after 3 days I finished the game. It was very fun.
Tried to make the build Demon's Slayer + Hellhound but no luck to pick these two together.
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What build did you finish the game with? As far as I can tell there are only 2 or 3 pieces that can possibly beat the game, because only those pieces scale exponentially. Grey goo+Gold Goo, Hellhound...???
With Hellhound alone I eventually had almost every space filled with hellhounds, and still couldn't get past level 10. That makes every other "good" piece look worthless.
It seems like one of the only builds that can do the 1000 dp/turn that you need to beat the 10th boss. If you got enough webbing you could theoretically do it with the Arakh, but I think your damage would accelerate too fast and you would end up facing the final boss without enough webbing to consistently deal 1000+ (you need 10 contiguous webs+arakh), or you would accelerate too slow and die on an earlier boss.