I HC that in the B ending it took quite a while for Dream to change,at first the only regret he had was not trying to find a way to change Nightmare's spirit sooner,then he he realises that chasing Nightmare for all those years to find a way to break their soul bond was cruel and unnecessary,slowly he comes to realisation that negativity is needed,but most importantly sacrificing one life for the sake of others is wrong
And after that he begins questioning his judgement on JR politics,who gave him the right to decide whether person deserves to die or not,how did their victims feel?Not everyone wants the person who hurt them to die.How many people live in fear of JR?
The blood on his hands could never be wiped away,but maybe he can at least atone for his sins by helping criminals get redeemed
