I think it's quite balanced, but it needs some 'limits' to prevent abuse. For example if antimattered one increases maxHP, a player could set up a PvP game to gain unlimited HP. I don't know if HP>100 affects rewards in PvP the same way it does in PvE, but if it does, it needs to be limited somehow (eg. no more than 200 MaxHP gained this way).
I also do not like the idea of cards that can affect the amount of electrum your opponent gains if he beats you.