The meaning of "madamada" in this context is "I'm not tired yet" or "I can still keep (fighting)".

if the following text is not "俺にやっつけられたいヤツは、かかってくるのだ！" but sth like "出直してこい(come back again)", "madamada" will mean "You're still have a long way to go before you can beat me", but in this case, from this following text " 俺にやっつけられたいヤツは、かかってくるのだ！", he wanna keep fighting, so that "I'm not tired yet" or "I can still keep (fighting)" is much more suitable.

The meaning of "madamada" in this context is "I'm not tired yet" or "I can still keep (fighting)".

If the following text is not "俺にやっつけられたいヤツは、かかってくるのだ！" but something like "出直してこい(come back again)", "madamada" will mean "You're still have a long way to go before you can beat me", but in this case, from this following text " 俺にやっつけられたいヤツは、かかってくるのだ！", he wants to keep fighting, so that "I'm not tired yet" or "I can still keep (fighting)" is much more suitable.