Esdeath and Prime Minister Honest were both the corrupting influence of the Empire, and the final antagonists of the series, but I like to think that their horror and callousness operates in different levels. I think Esdeath represents the cruel dimension of nature. She applies to human society the same rules that operate within the natural world. Within this mental dimension only the strong survive, and the weak are rooted out without mercy.
This parallel to nature is fortified by the fact that Esdeath summons an “Russian Winter”, and is thus compared to a natural disaster.
If Esdeath is the merciless force of nature, Prime Minister Honest represents the horror of the modern, political society. Honest is the stereotypical politician of modern day, who cares for no one other than himself, and cementing his own power. He seems to have no ideals, other than getting more power. Honest embodies the horror of living under a totally corrupted, dictatorial rule.
The almost never ending hunger for more power, is probably symbolized by the authors showcasing Honest almost always eating something, when he is on screen. Then again Esdeath lives for war, and always seeks more conflict to appease her symbolical appetite for battle.
I also find their deaths interesting, since they seem to be total contrasts. While Esdeath is defeated by Akame and she dies because the curse enters her body, I think Esdeath managed to attain a level of control over hear death.
She seemed to freeze her entire body and shatter it, before the curse killed her. By saying “Now I die”, she decided herself how and when it is, that she will die. All in all I think Esdeath`s death is an elegant and somber one. The reader is shown how even thou all of her power, Esdeath was not able to win Tatsumi´s affection.
Honest´s death is a total opposite of this and truly horrifying. Honest has zero control over the way he dies, and his death is long and agonizing one. He is tortured and sliced to pieces by the citizens of the Empire, and it takes a long time until he finally perishes.