Good list for a 650 points
My personal opional if i was making mono-khorne would be to change the cannon and stick the herald on a blood throne and remove the bloodcrushers and just get more bloodletter units because of the Totem of endless bloodletting buff you will only ever need him and every unit around him at least 1 model within 6" benifit from his loci as if he was in the unit give everyone around him locus of wrath it couples nicely with khornes special rule of charging into combat giving them +1 strength. The throne being able to heal itself and having 3 attacks from the herald and 3 attacks from the blood throne and 2 from its crew makes it really strong in
CC that and it gets a +3 armour save and a 5+ ward save because its a daemon of khorne too making it really hard to kill. Now lets talk about the gift's remove it and replace it with a
BSB this is on page 89 this meens if any units around you 12" of this model gets re-rolled failed leadership tests this will help with those double ones if you fail combat.
Hope this helps