Plus tu détiens de ces/les pavés, plus nombreux sont les sorts auxquels tu es autorisé à recourir.
A couple of points I can’t find answers for, even after referring to some similar posts in the past:
When I want to say "the more of these/those/the tomes you have" instead of "the more tomes you have", is it acceptable to say "plus tu détiens de ces/les pavés" instead of "plus tu détiens de pavés"?
In the second half, I opted to use inversion due to the long subject. But for the sake of argument, if the subject were the pronoun "ils", should I say "plus ils sont nombreux" without inversion?
If you swap the noun "pavé" with "pain", for instance, do you still need to pluralise the word, like "plus tu manges de pains"? Or is it more like "plus tu manges de pain"? The same question goes for the noun "eau".
de ces does the trick perfectly. de les would become des... but it sounds strange, I think you cannot translate the in this case, it would be de but it's more a translation for of tomes.
In this same case you could say: plus les sorts auxquels tu es autorisé à recourir sont nombreux ; with ils I can't find a correct sentence. plus ils sont nombreux auxquels tu es autorisé à recourir sounds really incorrect to me.
EDIT - You must replace les sorts with ceux and not ils: Plus tu détiens de ces pavés, plus nombreux sont ceux auxquels tu es autorisé à recourir. Of course ceux seems to refer to les pavés in this context, so you must be careful.
Don't pluralise it (pain or eau). You can say de ce pain or de cette eau if you want to translate of this bread or of this water. If you want to say some breads among others or some waters among others (it can have sense in some contexts) like for the tomes, you pluralise it but it's not exactly the same meaning, like in English I suppose.