Reasons to hate the lord's my opinion
Edelgard - Starting a war, Slithers (these two general reasons)
Dimitri - Tortured people, redemption was not handled the best and no real end goal for Fodlan.
Claude - Goes of to Almyra when things go ugly, demanding the book (Byleth in grieve scene) too preachy clean in comparison to the other lord's.
Special mention Rhea - Her inactions.
I do love all these characters.