Contradiction with Romans 12:19
This verse advises against taking vengeance, while Esther 9:26 describes the celebration of Jewish victory and revenge over their enemies.
Romans 12:19: Dearly beloved, avenge not yourselves, but [rather] give place unto wrath: for it is written, Vengeance [is] mine; I will repay, saith the Lord.
Contradiction with Matthew 5:44
This verse commands to love your enemies, while Esther 9:26 deals with a historic act of overcoming and defeating one's enemies.
Matthew 5:44: But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;