honestly, just having something to identify you as being a person interested in specififc things like this thread is based on. i would definitely +1 this, even if its only skill "chalenge" meaning you start a card battle. winning exp for beating the other player, leveling, not as an indicator of how good your cards are, but as an indicator for how many people you beat.

it only has one downside, which i think would be easy to live with. for lowbies, it would be obvious by looking at their gear or their level. this could mean they just started, or they could npot have good cards, and the high levels could target these people for easy wins. it is s0omething that could easily be worked around. i think a special class would be a good idea