I couldn't read one kanji, so the sentence could sound entirely
different. I think it meant to either say that Duel Monsters destroying
the world is the "correct" future, or that Paradox wants to change the
future to the "correct" one (what he thinks is correct). It could be
likely he wants to save the future for more than just for the sake of
future existence. If you think about it, he lost everything - his world,
he probably witnessed a lot of people dying, and his life, in a sense.
Whatever he was doing in his present was completely destroyed, with only
him remaining, or survived with very few people. Atsushi Tamura
mentioned Paradox carries great grief on his shoulders. Maybe he was
twisted by the trauma, or couldn't accept his fate, or both.
He might have someone special for him. Or he might just want to regain the life he lost thanks to Duel Monsters.
The mask's symbolism comes into play again - he may be twisted because
of what he went through (the "happy" side) but he also carries great
sadness ("sad" side). His mask could also represent him keeping his true
intention a secret, just like Bakura showing Mask of Darkness and
symbolizing Pegasus' way to hide his true intentions.