I'd use those skills for Nefarious purposes. But that'd be no good wouldn't it?
I'd be up to no good with those skills. We can't have that can we?
悪用はいけません。。。。ね
I'd use those skills for Nefarious purposes.「僕ならそのスキルがあれば悪用に使います」 But that'd be no good wouldn't it?「でもそれはいけませんね」
I'd be up to no good with those skills.「俺がそのスキルがあればいいことができないと思います」 We can't have that can we?「それはわれわれは許せないことですがね」
1) I want to use that skill for bad purposes but that's not good is it.
2) I want to exploit that skill for bad purposes but that's a no no.
1) & 2) "そのスキルを悪用したいところですが、それはダメでしょうね" という意味です.
I want to use that skill : そのスキルを市使用したい / I want to exploit that skill : そのスキルを悪用したい
for bad purposes : 悪い目的
but that's not good is it : れはダメでしょうね
but that's a no no : それはダメダメ (日常会話)