Isn't "clubs" always plural (and without article) in English in the context of playing cards?
(Also, I'm not sure what it would mean for a suit to be against a group of face cards, but I suppose there may be card games that use such terminology.)
I thought the rule was that the second verb always goes at the end? Is that only if the first verb is a "modal" one? If so, what is a "modal" verb and why isn't is/ist considered one?
I thought the rule was that the second verb always goes at the end?
Yes, but there is only one verb here: ist.
Did you think gegen was a verb -- perhaps because it happens to end in -en? It's not. It's a common-or-garden preposition. It's no more a verb than "against" is.