kuso means kid no?
kisama meaning you bastards?
Kuso sometimes means like 'crap' or 'sh!t' or 'damn'. There isn't really an exact word for it in English. It depoends on the context or preference of translation. Kid in Japanese can be kodomo, or if you want to be rude, gaki, it's like brat.
Kisama is not exactly like bastard. Literally, it is a very polite verson of saying in English 'you' but these days it is now understood as an insult, especially if it is used towards someone who is lower than you (age, job, experience...). I'm not entirely sure how to explain it, other than teacher said never to use it unless you want to really anger or upset someone.
Japanese have quite a few words that when translated literally into English do not sound rude, but spoken to Japanese people in the native language, they can be mildly rude or very insulting. Words like damare for example would be like using 'shut the fck up' or just 'shut up' in English, but literally in English, it does not mean exactly that.
That's why I always feel sorry for people who have to translate Japanese for anime, because depending on context or situation of the conversation, who is talking to who, ranking of people, and all the prefix/ suffix problems, it can be difficult to convey the exact feeling from Japanese to English. Transators just do the best that they can.