Re: SEWing Suggestion Zone, yay
The way I had it designed before was about 4 different titles to earn, which means 4 tiers of bosses to overcome. When I say bosses, I just mean that they're the representation of the bottom line of power level that that tier represents. And that's just talking about things like SEWing points and actual stats. The shop was pretty much gonna allow buying buffed up cards, and increasing your stats for a sharp cost. With the idea being that actual stat boosts are going to be x10 the cost of buying a card, and getting buffed up cards is equivilent to getting 5 cards that function as a stat boost of some kind. Sorta making the cost of the cards match since the actual stat boost will only come into play 1/10 of the time, and will add variety to your deck while starting you out simple and easy to understand.
Back when I had grapple cards, I'd have made a Special Card do something like, (When this is played and sex damage is dealt, +2d10 pleasure to opponent.). The issue I had at the time was deciding to randomize things or just allow people to purchase the # of the card (1-5) and apply an associate condition to it. Since all that was a lot of work I never got around to it.
Also again, I think 3 separate types of champions of all 3 genders would be appropriate.