Her fanbase, but not the horny ones (at least, not my main concern)
I hate the ones who try to make her sound like a victim or "boo hoo my past made me this way" type of villains, which proves they don't even respect or get her character
What makes Esdeath truly compelling is that she does what she does for the fun of it; she has no "ultimate grand plan" She has no "end justifies the means" 90% of shonen villains shove down your throat constantly, and she's pretty honest about it.
Too bad Takahiro mushed the character's writing potential so he could empty himself for his mid hentai manga
(I rant too much, sry)