Reputation Point = RP, could serve as both HP (once you [or a card?] runs out of rep it's suspended/dies) and attack (-1RP to downvote)
Maybe DV should cost -10RP for balance
But yeah maybe as a baseline, rep-type characters could use a downvote attack, in addition to specialized character-specific attacks?
And I'm guessing we'd have other types, like sock-type and bot-type cards