This is me guessing, but maybe the reason Cliff disappeared is because he turned into mana or something to keep Leon alive.Just like Nergal said, anything that came from another dimension rejects it from their world, and from the time Cliff was gone, Leon became strong...And the reason why Leon became weak was that the mana or something that Cliff left kept on depleting because Leon kept on using it.This is just a theory, don't bother me.
This is a good theory, thank you
This is me guessing, but maybe the reason Cliff disappeared is because he turned into mana or something to keep Leon alive.
Just like Nergal said, anything that came from another dimension rejects it from their world, and from the time Cliff was gone, Leon became strong...
And the reason why Leon became weak was that the mana or something that Cliff left kept on depleting because Leon kept on using it.
This is just a theory, don't bother me.