my two cents after finally beating the entire game with as little goblin generations as i possibly could.
pseudo guide:
-keep one generation 1 gob, call him OG. he'll provide the ritual fodder.
-dump all atk foods into one gob and breed it with the best atk girl you have without skills. only add to favorite the highest atk son. keep doing this while following the next steps.
-rush to conserve energy girl->rush to stealth girl.
-stealth+conserve energy-> super early cheese beats 99% of fights. it can be a gob with 1 atk and it still works, if you get a champion with it for high retaliation damage+a pack of champions you'll cut the time you're mouse clicking stealth by 50 times
-a strong stealthed champion will win most defensive fights, but in preparation for the last fights, we need some extra cheese.
-rush magic force girl (need to wait for hero party) get pressure girl in the meantime and strategy girl.
-combine for firetrap, combine for unlimited magic, then firetrap+stealth x 3 + u.magic+stealth and that squad clears 99 of anything in any difficulty. (when retaliation dmg is too low due to high def, dealing 90 per turn is op as heck)
-now we only need a cheese for the final fight, and we don't have the stats for it since we're a low generation run, even a gigastrike buffed to the wazoo will deal no dmg to the last fight.
-however, with our broken firetrap squad we don't need to care for anything else regarding bloodlines and what not, so simply use the following lineup
Last fight specific 100% win:
-all 4 of them using magic shields for rng protection on the first turn.
-set 3 invincible traps, even if they get debuffed, it will add a second layer of protection since it only debuffs 2 at a time.
-two backliners with psalm(drain 3 sp), to instantly drain the sp of the boss so it can only resort to basic attacks.
-one of the backliners needs infinity wave (0 sp cost + healing) the other backliner needs firetrap.
-one frontliner can run literally anything since it will get oneshot, and you just load until they take the hit first. you can even put guts on it for a final layer of rng protection.
-the one goblin bloodline at the very beginning, the one where all your atk foods went is coming here for the hardest cheese possible. you have two choices, one is easy, the other is a little bit tryhardy.
A) use armor shredder (very early skill, ignores def) + frenzy(50%crit chance) this makes your atk stat deal true dmg, which is enough to put the boss down.
B)sword dance (3 times 0.5 atk) + demon sword (+60 on all attacks) from my testing, thte +60 flat dmg is added thrice to sword dance, making it a 180minimum skill on a single target, which the boss is. if your unit is dealing barely 1-10 dmg to the boss, adding 180 is busted. we will ignore the fact that if your atk where high enough, you wouldn't care about 180, this is a low generation run after all, and we don't have time for that.
-at this very lv of investment, A and B setup deal around the same damage. armor shredder pulls ahead in normal runs if you got a lot of atk foods on your gobs, but since we're breeding less than normal, it's competitive to run either.
all you need to win the fight is that the first attack that you can't negate does not oneshot your dmg dealer and the infinity dude. the others can eat dirt on turn 1 since you won't fully drain the sp of the boss unless your spare frontliner also had psalm.
TLDR: the lowest generation of gob i managed to follow this run (so far) is gen 15(and only for the main dmg dealer, otherwise boss escapes on the one fight you get with it)
the early game is rng if you get a champion/pala/lord on your first breeds and it's gg for every mandatory stage up to conserve energy, then you sac every goblin in order to beat your way up to stealth. and after that you basically auto click and do 2-3 generations for the mandatory skills.
is it fun? perhaps not since it requires some form of load scumming for rituals and what not.
it's even more viable in ng+ as long as you got at least one conserve neregy+stealth gob alive.