Not Pure Variant Drop

I think that when you would noramlly get a variant it would make sense to give a variant for high use cards that the player doesn't have any variants for.  Maybe to increase the chances of giving a variant for a card you have no variants for before giving a variant for a card you already have a variant for.

If I have 3 infinite Iceman cards and no variants, and 3 infinite Korg cards and no variants, and 3 infinite Magneto cards and no variants .... these are clearly cards I value.

Instead I've gotten two Strong Guy variants (a card I've never once used, so these variants obviously have little value for me as a player) ... two Adam Warlock variants ... 

I don't mind having two Agent 13 variants.  At least I use that card.  I'm not upset about having an Uatu variant even though I've never played it.  It's a single variant for a card.  No big deal.

I think you should add weight to the odds of what kind of variant will be drawn.  Obviously more likely to be a rare than a super rare (though the super rare drop rate feels too low).  But, the cards that get used the most should be weighted a bit higher for drop rate.  And, the cards that a player has gotten zero variants for should be weighted higher for drop rate.