Beware the Time Machine!

Mamo Kyosuke claims that Lupin will disappear from the world in four days. He claims that he is a time traveler from 2874 seeking revenge.
Apparently, Lupin XIII destroyed the Mamo clan on 31 March 2874; Kyosuke has traveled back in time to destroy Lupin III preventing his clan's future destruction.
Kyosuke backs his claims up by traveling into the past and killing the builder of a castle causing it to disappear in front of Lupin's eyes. As time runs out for Lupin, can he discover Kyosuke's secrets? Is he all he appears to be?