Because so far it hasn't been hinted that strength is the key to stopping the infection. That's where David's theory comes in.Originally Posted by NeoCybercoin
As for fusing...I don't believe they've ever done that before. The fusing of flesh is the closest thing we've seen so far, and that's been portrayed as the simple insertion of youma flesh into a human.
As for the new tower of destruction (forgot the name), they managed to fuse because they were sisters, if I'm not mistaken.