Grammar difficulties in sentence with adjective + さんには

Question

I'm playing a game and the following was said:

ふうん。。。あなたには情報を提供しているんですよ？ これで見つけられないような役立たずさんには。。。

My confusing comes in with the second sentence. I'm not sure what the bold portion (さんには) is trying to convey. I'm not really sure what the さん part is at all and how it works with the には part. My best guess is that it is really is さのには, but even then what does this actually mean here?

When trying to translate it I think its something like:

Well... Can you provide any information? Because of this, not being able to find it is as if it is useless.

Context: The main villain asked their right hand man how the investigation is going for an item. They responded by saying they have still have not obtained it. Then the main villain says the above

Answer 1

It's 役立たず-さん, さん as in 田中さん， i.e. Mr (Ms) Useless.

あなたには情報を提供しているんですよ？

I [= the villain] have provided you with information [for the investigation for the item]. {Maybe I'm providing you fits better.}

これで見つけられないような役立たずさんには。。。

[For] Mr Useless who can't find it with this [information the villain has provided]... What's being omitted is not clear, perhaps along the line of 「罰が必要でしょうか」 There needs to be a punishment, I wonder?

If I may judge without context, not simply saying "これで見つけられないような役立たずには" adds the the villain's character more politeness (which, in this case, implies certain kind of deep evilness), intellect, pedanticness, and/or sophistication.

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For the former part

あなたには情報を提供しているんですよ？

I'll try to explain.

(1) From the part "あなたには" it is clear that "あなた" isn't the one who gives the information. A が B に C を提供する = A provides B with C.

(2) I wasn't able to come up with a situation where "-ですよ？" can be a question: ですか？ (or more casually, です？) would be a question.

(3) 「提供している」doesn't refer to an action which hasn't taken place. It's either "A have provided" or "A is providing".

If you give more detail about your confusion, I (or somebody) could write an answer more spot-on. But in that case, I think it should be posted as another question.