I personally took my Odin card from Landanel (sp?) using my 2* capped deck which I consider to be the toughest challenge this game has offered so far. What they need to do is not make random so one-way. Random NPCs have such a small card variety that despite the rule, you already know what they're going to have. It's barely any different from NPCs without the rule. But we spend so long getting the easy cards first that we have a disproportionate amount of poor cards to our good ones making it unlikely that we'll even have one card above our cap.

I appreciate it when a game dares to frustrate its players because it invites memorable moments, but that's much better done with trail and error encounters. There's no waste of time more disheartening than one that you can't speed up through skill nor calculate the ending of. That's what separates this from a standard grind.

At the very least, it would be beneficial to a players motivation if they made one or more of these changes to the random rule:
-Double or triple each Random NPCs card pool
-Guarantee that are cards are on cap (so if you have a 2* cap you won't get any 1* etc)
or instead of that last one
-Abolish our rarity cap while the Random rule is in play (making it truly random and giving us a shot at occasionally having the better deck instead of only ever being weak or super-weak