I am watching a certain show at the moment where someone is talking about wanting to kill evil creatures. Please don't judge this question as childish just because the extract is from an anime.
I understand that, but then he says
I don't understand why he would say もっとだ. The reason why is that I don't know what he is saying exists as 「もっと...」, if you understand what I mean. I know the meaning of the word, I just don't get why he would say だ afterwards. Like, if I asked in Japanese I would say... 何が「もっと」ですか？ What would replace 何 in that question?
Is だ just emphasis of how much he wants to kill more?