well, you probably are not summoning enough minions? i don't see any bugs in the code and it works fine for me, so
spoilers
spoilers
spoilers
spoilers
spoilers
spoilers
the requirements is
"potence" + minions OVER 10
and divine order equaling 100
each time acoite lazes around during the weekends he gets 1 "potence" point; each time he summons minions, he summons 3 of them.
some follower events and choices make him spend potence points tho, so you gotta let him laze from time to time throughout the story. . . and if you're aiming for true ending dont forget to let acoite spend time with theodore. . . and im very sorry to tell you that chtulhu fight is not even the last difficult stat check. . .
wishing you all the luck. . .