Mystic is when Gohan loses the power to become SSJ, but he doesn't need it, since Mystic pretty much covers SSJ, it's kind like not needing SSJ to increase speed and power, and the amount of PL you get is expanded greatly. Gohan loses the power when he gets the Zet Sword, which is a mystic type of sword, much like Trunks' sword, which was Tapion's (By what I heard). These swords will probably end up doing a good deal of damage, and both Gohan and Trunks will end up being in close fighters with a deadly melee attack by just using their swords.
Not enough people use the Punch and Kick, you know. So the addition of Tapion's Sword and Zet Sword will be a warm welcome to the over all game play, and the block will probably turn into a sword parry as well. I'm very excited upon hearing of the addition of Tapion's Sword and possibly Zet Sword, as it'll raise the chances of people fighting Melee style to a new level. Hopefully we'll see the Chou Kamehameha, and more unique disk features as I also said in another post, where block catches the disk if you have a high PL (or the sword block destroys it.. that would be pretty sweet, ne?), where the disks charge as you slowly move, and when you fire these off, you don't move, at all. the Disks become smaller, two are launched at once, etc.
~Ryu