Meaning of “Resba(レスバ)”
“Resba(レスバ)” is an abstraction for “response battle”.
It means quarreling (on internet).
This is an internet slang.
Example Conversation
A: What do you think who is the strongest on resba(レスバ)?
B: I don’t care. Resba is a waste of time, I think.
A: レスバ最強って誰だろうね。
B: どうでもいいかな。レスバって時間の無駄じゃん。