Only if it unbalances you - you want to be in the middle not too yin or too yang.
If you are too hot, taking yin energy would be beneficial. E.g., if you are already feleling yin - meaning having yin state of being, like being cold, depressed, low motivation, quieter than usual, low energy, unassertive etc… it could push you to be colder and make the unwanted side of being yin worse.
But, if you have a fever, you can cool yourself down by pulling energy from the Earth, or even the Arctic, which is cold. If you feel cold or depressed, it would be better to pull from the Sun to warm yourself up with yang energy, and restore your balance.
If you mean “dark” as in “black magick, bad intentions” dark, then this is not a quality as much as an intention. Energy by itself doesn’t judge what it’s used for.
Energy is the tool, a hammer is not good or bad, it’s the person using the hammer and his intention, and the judgement around that that make it bad or good.
Yin and yang are relative - and yin means more dark, quiet, soft, yielding, small than yang which is brighter, louder, faster, bigger, stronger, harder, more aggressive.
So “dark” is maybe not yin for your purposes.
Right so it’s the intention that’s “dark”, more than the technique. This may not affect how you do the work, but how you use the info you get out of it.
But then this, also says your intention is light and yang, as you are protecting potential victims.
This is where the judgment part gets really obvious - those victims will never know you saved them, but they would probably judge you as light, almost an angel helping them, while the criminal would see you as dark. Sometime good people have to do bad things to bad people, and the actual evil thing to do would be to avoid responsibility and do nothing.
“All it takes for evil to prosper is for good men to do nothing.” As they say.
