Welp, imagine being me and actually liking Momo as a character when she was there during the early parts of the story, only to see her get knocked out and then wonder "wow i liked Momo but she hasn't appeared in a billion chapters, i wonder if she'll reappear, did the author forget about her or something?";
and then when she finally reappears, she has become a witch, acting incredibly evil & stupid (and getting made fun of for that) only to then be fed to the most liked character in the series in the span of 2 chapters.
Geez, forget about the author forgetting her, seems like instead he had a specific grudge against her and was just biding his time to show it, i can't even say "damn that's a bit much, give her a
bit of a break maybe?" 'cause you just know there's more to come against her having become a witch and all.
Oh well, what can you do i guess